Material Revolution: Sustainable and Multi-Purpose Materials for Design and Architecture 9783034610773, 9783034606639

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Air Clean ® wall paint 155 Akromid ® S 40 Alkemi ™ 78 Alulife ® 77 Alulight ® 104 Alusion ™ 78 Ambient Glow Technology – AGT ™ 171 Amorim ® 51 Arbofill ® 56 Arboform ® 38 AR-hard ® 156

B Product index 3mesh ® 116 3XDRY ® 119

A Accoya ® 48 Adhesive textiles 191 Admonter ® 48 aerofabríx ™ 116 Aerosil ® 156 AgPURE ™ 157 Agriboard ™ 86 AgriPlast BW 38 Air Clean  ® cobblestones 155

Balsaboard 86 Barktex ® 58 Batyline ® 84 Baytubes ® 120 BeeCore ® 96 Bio-based polyamides 40

Bio-based resins 40 Bio-based soft foams 40 Biofiber ™ Wheat 56 Bioflex ® 35 Bio-Glass ® 79 Biograde ® 38 Biomax ® TPS 37 Biomer ® 36 Bioni Hygienic ® 157 Biopar ® 37 BioplastTPS ® 37 Blazestone ™ 79 BlinGcrete 175 Blue Angel 91 © Buzzispace 84

Cartamela 88 ccflex ® 147 Celbloc Plus 149 Cellucomp ® 56 CenoTec  ® 118 Chromicolor ® 145 Climacell ® 107 Cocodots ® 46 Coconut Tiles 46 Cork 108 CurV ® 121

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Dakota Burl ® 56 DalLastic ® 74 Dämmstatt ® 107 DigitalDawn 171 Dines ® 145 Doluflex ® 78 Dual-component ceramic foam 103 Duocel ® SiC Foam 103 duraAir ® 155 Durat ® 73 Duripanel ® 86

Calymer ™ 102 Capa ® 66 Capromer ™ 66

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E Ecogehr ® PLA 35 ECOGEHR ® W PC 45 Ecopan ® 87 Ecovio ® 35 Edilfiber ® 73 Elvanol ® 65 Enka ® -Moss 152 Envirez ® 40 Environ biocomposite ™ 90 Essemplex ™ 127 Eurolight ® 96

F

G

I

Fasal ® 45 Ferrotec 148 Fibertex Pan ® 84 FIBRIL™ 120 Fibrolon ® 45 fineFloc ® 107 Fireclay ® BottleStone 82 Firstwood ® 48 Flamexx ® decotech 96 Flupis ® 106 foamet ™ 104 Foamglas ® 81 Frontier Carbon Corporation 120 FSC 91

Glassshells 80 Globocer ® 113 Globomet ® 113 Gohsenol™ 64 Green LinE ® 55

Icestone ™ 79 Ingeo™ 35 InstaCoustic Cradle ® 74 Isofloc ® 107 isolcell ® 90 Isolgomma RTA ® 74 Isolith ® 88 Isospan ® 88

H Hailstone © 80 Homasote ™ 90 Hybrix ® 98 HyProtect ™ 157

K Keridur ® 73 Kovalex ® 45 kraftplex ® 87 Kupilka ® 45

MATERIAL REVOLUTION

Sascha Peters

MATERIAL REVOLUTION SUSTAINABLE AND MULTI-PURPOSE MATERIALS FOR DESIGN AND ARCHITECTURE

Birkhäuser Basel

contents

I introduction

Sustainable and Multi-functional Industrial materials – The Material Revolution…006 — The Importance of Creative Professionals for Technical Innovation…012 II MATERIALs

Bio-based Materials…030 — Biodegradable Materials …060 — Recycling Materials…068 — Lightweight Construction and Insulation Materials…092 — Shape-changing Materials…122 — Multifunctional Materials…140 — Energy-generating and Lightinfluencing Materials…160 — Sustainable Production Processes…178 III appendix

About the Author…195 — Index…196 — Biblio­ graphy…205 — Selected Publications by the Author…206 — Selected Lectures by the Author…207

1 BIO-based Materials

5 Shape-changing materials

Bioplastics Based on Polylactic Acid…034 — Bio­­plastics Based on Polyhydroxybutric Acid…035 — Bioplastics Based on Thermoplastic Starch…037 — Bioplastics Based on Cellulose…038 — Bioplastics Based on Vegetable Oils…040 — Lignin-based Bioplastics…041 — Algae-based Bioplastics…041 — Bioplastics from Animal Sources…042 — Acrylic Glass Derived from Sugar…043 — Natural Rubber…043 — Wood Polymer Composites (WPC)…044 — Coconutwood Composites…046 — Bamboo…047 — Heat-treated Natural Woods…048 — Thermo-hygro-mechanically Compacted Wood (THM)…049 — Cork Polymer Composites (CPC)…050 — Almond Polymer Composites (APC)…052 — Algae-based Materials…053 — Fungusbased Materials…054 — Natural Fiber Composites (NFC)…055 — Linoleum…057 — Bark Cloth Materials…058 — Maize Cob Board (MCB)…059

Shape Memory Alloys (SMAs)…126 — Shape Memory Plastics (SMPs)…127 — Thermo-Bimetals…128 — Piezoelectric Ceramics (PECs)…128 — Piezoelectric Plastics (PEPs)…129 — Electroactive Polymers…130 — Buckypaper…131 — Hydrogel…132

2 Biodegradable materials

Water-soluble Polyvinyl Alcohol (PVOH)…064 — Alkali-soluble Plastics…065 — Polycaprolactone…066 3 Recycling materials

Recycling Plastics…072 — Recycling Elastomers…074 — Recycling Steel…075 — Recycling Copper…076 — Recycling Aluminum…077 — Recycling Glass…078 — Foam Glass…080 — Recycling Solid Surfaces…082 — Recycling Textiles…083 — Bonded Leather Materials…085 — Wood Compound Materials…085 — Wood Concrete…087 — Paper Made of Organic Waste…088 — Recycling Paper…089 4 Lightweight construction and insulation materials

Honeycomb Structures…096 — Double-webbed Panels…097 — Stainless Steel Micro-Sandwich…098 — Carbon Fiber Stone (CFS)…099 — Ultra Highstrength Concrete…099 — Basalt Fiber-reinforced Materials…101 — Plastics Refined with Mineral Particles…102 — Ceramic Foam…103 — Metal Foam…104 — Wood Foam…105 — Paper Foam…106 — Cellulose Flakes…106 — Natural Fiber Insulation…108 — Rigid Polyurethane Foam…110 — Vacuum Insulation Panels…110 — Aerogel…111 — Hollow Sphere Structures…113 — Technical Textiles…114 — Spacer Textiles…115 — Membrane Textiles…117 — Nanotextiles…118 — Carbon Nanotubes (CNT)…120 — Selfreinforced Thermoplastics…121

6 Multifunctional materials

Biomimetic Materials…144 — Color and Transparency-changing Materials…145 — Dirt-repellent Surfaces…146 — Electrorheological and Magnetorheological Fluids…147 — Phase Change Materials (PCM)…148 — Loam…150 — Moss…151 — Zeolites…152 — CO2-absorbing Materials…153 — Scent Microcapsules…154 — Nano Titanium Dioxide…154 — Nano Silicon Dioxide…155 — Nano Silver…156 — Nano Gold…157 — Nanopaper…158 — Self-healing Materials…159 7 Energy-generating and light-influencing materials

Photovoltaic Materials…164 — Thin-film Solar Cells…165 — Multiple Solar Cells…166 — Black Silicon…166 — Green Algae…167 — Thermoelectric Materials…168 — Ferroelectric Polymers…169 — Lightemitting and Luminescent Materials…170 — Light-emitting Diodes (LEDs)…172 — Organic Light-Emitting Diodes (OLEDs)…173 — Multi-touch Films…174 — Retro-reflective Materials…174 — Translucent Materials…175 — Metamaterials…176 8 Sustainable production processes

Multi-component Injection Molding…182 — InMold Techniques…182 — Metal Injection Molding…183 — Incremental Sheet Metal Forming…184 — Free Hydroforming…185 — Laser Beam Forming…186 — Arch-faceting…186 — Additive Forming…187 — Laser Structuring…187 — 3D Water Jet Cutting…188 — Multi­f unctional Anodizing…189 — Dry Machining…189 — Adhesive-free joining…191

6

Sustainable and multi-functional industrial materials – the Material Revolution

Vases made of algae fibers, cell phone casing of tree bark, coffins of almond shells, mosaics of coconuts and bicycle frames of bamboo: These are just some of the most striking examples of a development that will take on a revolutionary character in the near future. Natural materials, recycled industrial materials, and product concepts that are sparing with resources are all gaining ground. The world is seemingly undergoing radical change; or so the ever more frequent environmental problems and the bio-based solutions with a low environmental impact that companies are now touting would lead us to believe. Materials are to be more natural, healthier and more sustainable. Nothing less is at stake than saving our climate, securing our standard of living and creating a basis for life for the next generations. Bicycle frame made of bamboo (Source: Craig Calfee) → p. 047

At the latest since it was recognized that supplies of fossil energy sources will dwindle in the coming decades and many raw materials be available in limited amounts only, intensive efforts have been made to find alternatives. The material innovations of the twentieth century, whose creation we largely owed to crude oil, will have lost their significance in a few years. Bakelite® (a duroplastic phenol resin) was used for the housings of the first electrical devices in the 1930s, polyvinylchloride (PVC) for records in the 1950s, polyurethane for body-hugging ski boots in the 1970s, and fiberglass-reinforced plastics for pole vaults. The general consensus was that material innovations with new mechanical properties and functional qualities gave birth to new product solutions. Cell phone casing made of bark cloth (Source: Bark Cloth ®) → p. 058

However, the upcoming meteoric advances in the materials sector will no longer focus on developing new functions. Rather, the aim will shift to producing industrial materials whose employment is sparing on resources, material-efficient and does not pose a danger to people. As consumers are becoming increasingly aware of the eco-friendly handling of materials and of thinking in material cycles, investment in sustainable products is a rewarding business. Indeed, in many areas customers even expect eco-friendly materials with multi-purpose properties and the use of sustainable production methods.

7

Ski boot with a “Hytrel® RS” bioplastic shaft (Source: DuPont)

Meanwhile the challenges appear to be so immense that political measures need to be taken to accelerate the change. The 2010 Copenhagen Climate Conference might have failed owing to the opposition of the emerging economies but the western industrial nations, and in particular Europe see there now being an opportunity to combine environmental policy necessities with the economic challenges so as to secure innovation competency. Consequently, the European Union has drawn up the 20–20–20 Climate Change Package, under which energy consumption and emissions are to be cut by 20% by 2020 and simultaneously, regenerative energies are to cover one fifth more of total consumption. Receptacles made of cellulose plastics (Source: Biowert) → p. 038

Companies believe the moment has come to carve out a distinctive image by using new products. For example, the market for bioplastics based on renewable resources such as cornstarch and cellulose, is expected to see an annual expansion of 25–30% in coming years. The chemicals giants and small to mid-sized goods manufacturers have

8

already developed numerous products and the range is increasing constantly. But whether the bio-based and/or biodegradable industrial materials really are climate-neutral has yet to be definitively settled. Generally, we lack reliable information on how many resources, how much water and energy is required in the course of a product lifecycle, from production via transport and use through to disposal. Only gradually are standards and measures emerging that enable objective comparisons to be made. Take the “ecological rucksack”: it has established itself as a means of depicting the total amount of resources needed in the manufacture, use and disposal of a product. It is normally employed for ecological balances together with the carbon footprint, which is the sum of all greenhouse gas emissions produced during a product’s lifecycle, or the “virtual water” measure, in other words, the amount of water needed to produce a product. When measuring the “ecological rucksack” of materials, we talk of factor 5 for polymers. This means that it takes about five kilos of resources to produce one kilo of plastic. As some 85 kilos of resources are needed to produce aluminum and an amazing 500 kilos for copper, recycling can no longer be ignored, especially for these mass materials. It will probably take some time, however, until reliable data on the most important materials exists.

Sheet material made of 100 % recycled glass (Source: Coverings Etc) → p. 079

Until such time as we have access to materials that have no negative impact either on the climate or the environment the key aim must be to make the best possible use of existing resources and select the most suitable material for any given purpose. It follows that enhancing material efficiency is a major aim of current research activities. For instance, coating systems in nano- or micro dimensions have been developed that optimize material properties, guarantee them over a longer period, and enable additional features such as high scratch resistance and easy-to-clean properties. Similarly, several manufacturers have pushed forward the development of materials based on recycled raw materials. Products are now available in almost every industrial material class, which considerably extend the use of resources. Metals, plastics and paper made

of recycled industrial materials can almost be described as classics. They have recently been joined by new materials made of recycled glass, recycled textiles, or mineral industrial materials, as well as by a collection system.

9

Fungus-based hard foam for packaging (Source: ecovative design) → p. 054

Research is being conducted into new production methods modeled on natural growth processes, which see the creation of material as a biological process. Moreover, agricultural waste products serve to replace conventional components in composite materials, thereby reducing the amount of resources needed. People now even expect materials that do not land on a rubbish dump on completion of their service life but can be used to produce materials for a new product. Lightweight structure, based on metallic hollow spheres (Source: hollomet) → p. 113

Given the long distances products and materials must travel from manufacturer to consumer, low-weight industrial materials and composite materials are gaining importance. Not only do they incur lower energy consumption during road or air transport, they also make assembly and handling easier. In architecture, using lightweight materials translates into less construction work and subsequently less material to realize buildings. Given global warming, those materials with CO2 storing properties will in future assume ever greater importance. Since some 40% of global consumer energy goes on the consumption and operation of buildings, energy-saving potential in the construction industry is enormous. Increasing importance will be attached to improving heat insulation. In this context, those materials that turn sunlight directly into electricity, can store heat and moisture and can contribute to natural air conditioning are of particular interest to designers and architects.

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With its entry to the 2007 and 2009 Solar Decathlons in Washington, Darmstadt Technical University proved what immense opportunities can be tapped by using innovative materials and new construction techniques. The team headed by Prof. Hegger employed a combination of vacuum insulating panels, cutting-edge solar technology, and climate-altering phase-change materials in a house that produced more energy than it consumed, and won first prize in the competition.

Team Germany, 2009 Solar Decathlon (Source: TU Darmstadt) → p. 149

While some manufacturers seek to reduce the environmental impact of their products by using renewable and natural resources, others are adopting a totally different approach. They develop materials that boast other qualities, alongside their mechanical functions. These include the ability to respond to environmental influences by changing shape or color, to store water while retaining a dry surface, or to repel soiling owing to surface properties. Recently many designers have expressed their interest in particular in materials capable of altering their shape; when a certain temperature is exceeded they automatically return to their original geometry. Nor should we forget the options created by material surfaces that can eliminate harmful gases and odors from the air, have an anti-bacterial effect or anti-reflection properties. It would seem that the classic mechanized understanding of materiality is giving way to a new materials culture, in which materials reveal multi-functional potential: they can be lightweight or dirt repellent, can change color or are retro-reflecting. But they all share a single purpose: to achieve a more responsible use of our global resources.

12

The Importance of Creative Professionals for Technical Innovation

The outlined change entails moving away from materials with onedimensional functionality that impact negatively on resources, to a material culture with multifunctional potential, holistic material cycles and sparing use of resources. In its course creative professionals such as designers and architects will assume a special responsibility. They are, after all, the people in material-related developments who typically select a material and influence production design. The responsibility involved comes from an altered perception regarding the role of creative professionals that has emerged in recent years. Indeed, one can even argue the traditional technology-oriented understanding of innovation is undergoing a reversal. Applications-related converters, designers and architects are becoming mentors with arguments based on conceptions, who in consultation with manufacturers either encourage the creation of new materials and production methods, or develop them themselves. New industrial materials with their desired qualities are conceived from the perspective of the user, and the necessary technical features designed for potential deployment scenarios. The focus is shifting from material properties to material performance. Designers intervene in the technological quality of material and define material behavior rather than having their decisions determined by it. Retroreflecting concrete (Source: Kassel University) → p. 174

Numerous developments of late illustrate this shift towards a culture of innovation that is decisively driven by the special perspective of creative professionals. A prime example is the development of a special concrete with retroreflecting properties (see Chapter 07). The idea stems from artist Heike Klussmann in collaboration with architect Thorsten Klooster. In the late 1990s Klussmann had already been involved in various art projects that sought to create special reflections in markings for road surfaces, car parks and subway lines. Some ten years later she successfully integrated her retroflection concept (an optical phenomenon whereby rays of light are always directed back in the direction from which they came, with minimum scattering) into mineral surfaces. An interdisciplinary development team of physicists,

engineers and concrete specialists is currently engaged in creating the material to mark danger spots and for retroreflecting surface lighting. Its special feel means the material can also be used for tactile guidance systems for blind people.

13

Translucent wooden wall (Source: Luminoso) → p. 175

Another example of how creative professionals act as enablers of future markets can be seen in the development of translucent concrete by the Hungarian architect Áron Losonczi. In close collaboration with technology leader, Schott AG, he embedded light-conducting fiber material into the mineral material and made it pervious to rays of light. Subsequently, several firms not only copied the product concept of the architect, who is a successful a producer in his own right, but also transferred his idea to other areas. In 2009, the concept of embedding light-conducting optic fiber into a material matrix was successfully applied to a wooden material under the name “Luminoso” (see Chapter 07). Heat Seats, temperature-sensitive seating (Source: J. Mayer H.) → p. 145

The fact that innovative materials and material surfaces are also suitable for graphic tasks was appreciated not by communication designers, but by several architects. Jürgen Mayer H. was one of the first to employ thermosensitive dyes in textiles and furniture design and demonstrated the amazing communication potential of fabrics and everyday objects as long as ten years ago. Since then, the idea has featured in numerous applications including wallpapers that respond to temperature shifts by changing color, glass that reacts to the intensity of the light striking it by altering its transparency, and concrete that reacts to changes in the weather (see Chapter 06). Dutch designers Frederik Molenschot and Susanne Happle treated concrete stones with a special surface coating that responds to water. The result: a floral decoration is produced whenever it rains. (Rain) water reveals hidden decorations on public squares and footpaths

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that make for a new symbolic language of urban quality. Under the name “Solid Poetry” the floral concrete creates a totally new feeling in public spaces.

Water-sensitive concrete (Source: Solid Poetry) → p. 146

As regards production techniques, “free inner pressure deformation” (see Chapter 08) by Polish architect and designer Oskar Zieta is an outstanding example of how the greater emphasis being placed on relevance to use also extends to production. The method became known in 2008, above all thanks to “Plopp”, an inflatable stool with startling aesthetics. In January 2010, at the IMM Cologne fair, Zieta demonstrated the technology for the first time using an architectural lightweight structure of highly polished sheet metal modules. In the production process the sheet metal is cut with a laser, welded together at the edges and then inflated using compressed air. Trade fair stand made of inflatable sheet metal elements (Source: Oskar Zieta; photo: gee-ly) → p. 185

Similarly, the use of metallic foams and foam structures in furniture and interior design was inspired by the work of creative professionals. One example is the luminaire designed by Andreas Robertz, which he “Twinkle Little Star” luminaire with foamed metal shade (Source: Zoon Design) → p. 104

developed during his time at the Welding Institute of RWTH Aachen University. Whereas in 2006, he was still using the lost-wax molding method based on a polymer foam to produce the component geometry, in 2010 he succeeded in producing it using the sinter technology of hollomet GmbH from Dresden.

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Designers are also currently exploring the potential of bio-based materials. Mehrwerk Designlabor, for example, specializes in developing products from natural fiber composites. To date, this material category was only seen as a substitute for petrochemical components. However, the aim pursued by the designers from Halle is to emphasize its particular material qualities and consequently, make the use of renewable resources competitive on mass markets and alert designers worldwide to the potential of bio-based materials.

Lounge Chair made of a natural fiber composite (Source: Mehrwerk Designlabor) → p. 055

Dutch designer Mandy den Elzen was the first to successfully use algae fibers in a composite material. She coated fiber strands with a special resin and produced three-dimensional receptacles with a natural appearance and a translucent structure (see Chapter 01). It seems likely algae will become increasingly important in coming years as a basis for other materials. After all, algae are being touted as a future energy source for the production of biomass or as a supplier of hydrogen, and are available worldwide. Cultivating them would not have a negative impact on food prices. Receptacle made of an algae fiber composite (Source: Mandy den Elzen) → p. 053

The construction of Bhaktapur Tower in Nepal (see Chapter 06) is an impressive example of how, given rising transport and energy costs, architects are assuming responsibility for the sustainable handling of material resources in the construction industry. All the building material

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was excavated from the building site or produced locally. Architects decided to forgo material from other regions of the world. Against the backdrop of current trends their concept would seem to be crying out to be imitated.

Tower of Bhaktapur (Source: Atelier Rang) → p. 150

Designers and architects recognize the opportunities and potential new materials offer and are increasingly becoming innovators of a new material culture!

1 BIO-based Materials 030 – 059

2 Biodegradable materials 060 – 067

3 Recycling materials 068 – 091

4 Lightweight construction and insulation materials 092–121

5 Shape-changing materials 122–132

6 Multifunctional materials 140 –159

7 Energy-generating and light-influencing materials 160 –177

8 Sustainable production processes 178 –191

Oskar Zieta, “Bones” Free hydroforming // Sustainable production processes → p. 185

Oskar Zieta, “Plopp” Free hydroforming // Sustainable production processes → p. 185

“Lo Glo” by Jürgen Mayer H. for Vitra Edition Light-emitting and luminescent materials // Energy-generating and light-influencing materials → p. 170

DigitalDaw n by Loop.pH Light-emitting and luminescent materials // Energy-generating and light-influencing materials → p. 171

Bark cloth based beaker by Mehrwerk Designlabor Bark cloth materials // Bio-based materials → p. 058

Pulp Collection by Jo Meesters Recycling paper // Recycling materials → p. 089

Hood with in-sew n shape memory alloys designed by Max Schäth Shape memory alloys (SMAs) // Shape-changing materials

→ pp. 125/126

Lamp with ceramic foam lampshade by Nextspace, serien.lighting Ceramic foam // Lightweight construction and insulation materials → p. 103

“Mossy Hill” installation by Makoto Azuma Moss // Multifunctional materials → p. 151

“Mossy Hill” installation by Makoto Azuma Moss // Multifunctional materials → p. 151

Indoor swim ming pool in Neydens, France. The building sheath was realized using transparent ETFE cushions on a wooden space frame. Membrane textiles // Lightweight construction and insulation materials → p. 117

OLED light branch by Hannes Wettstein Organic light-emitting diodes (OLEDs) // Energy-generating and light-influencing materials → p. 173

“E-Static Shadows” light installation by Zane Berzina Light-emitting diodes (LEDs) // Energy-generating and light-influencing materials → p. 172

“E-Static Shadows” light installation by Zane Berzina Light-emitting diodes (LEDs) // Energy-generating and light-influencing materials → p. 172

Uses of Luminex ® Light-emitting and luminescent materials // Energy-generating and light-influencing materials → p. 171

30 BIO-based Materials

Bioplastics Based on Polylactic Acid…034 — Bio­­plastics Based on Polyhydroxybutric Acid…035 — Bioplastics Based on Thermoplastic Starch…037 — Bioplastics Based on Cellulose…038 — Bioplastics Based on Vegetable Oils…040 — Lignin-based Bioplastics…041 — Algae-based Bioplastics…041 — Bioplastics from Animal Sources…042 — Acrylic Glass Derived from Sugar…043 — Natural Rubber…043 — Wood Polymer Composites (WPC)…044 — Coconut-wood Composites…046 — Bamboo…047 — Heat-treated Natural Woods…048 — Thermo-hygro-mechanically Compacted Wood (THM)…049 — Cork Polymer Composites (CPC )…050 — Almond Polymer Composites (APC)…052 — Algae-based Materials…053 — Fungus-based Materials…054 — Natural Fiber Composites (NFC)…055 — Linoleum…057 — Bark Cloth Materials…058 — Maize Cob Board (MCB)…059

— 01 —

31 BIO-based Materials

32 BIO-based Materials

Foams based on castor oil, disposable crockery from potato starch or plastics with carrot fiber reinforcement: intriguing examples of how bio-materials can be employed. In recent years these materials have experienced a meteoric development. They are made up completely or to at least 20 % of renewable resources. As a result, in coming years crude oil in particular will lose its significance as the base for plastics production. For bioplastics alone, through 2020, annual growth rates of 25–30 % and a rise in production capacity of around 3 million tons (currently 350,000 tons) are expected. In packaging in particular, thermoplasts made from petrochemicals such as polystyrene, polyethylene or polypropylene will be replaced in the medium term by biopolymers. The raw materials involved in these diverse developments are natural polymers such as starch, rubber, and sugar. The lion’s share is taken by thermoplastic starch (80 %). That said, substances such as lignin, cellulose, chitin, casein, gelatin and vegetable oils will also be used to produce bioplastics. Polylactides and polyhydroxybutyric acids are sourced from natural polymers and already employed in totally different sectors. Alongside bioplastics, biocomposites represent another important group of bio-materials. These include plastics reinforced with natural fibers and wood-plastic composites (WPCs). Thanks to their special surface structure, as well as sound and vibration-absorbing properties, cork-polymer composites are being used for sports articles and interior work.

33 BIO-based Materials

“Fragments” sculpture using bio resin (Source: Galerie Adler; artist: Gregor Gaida)

Disposable PLA-based beaker (Source: NatureWorks ®)

Processing foils made of bioplastics (Source: alesco)

Classification of bioplastics by origin RRM = renewable raw materials from RRM, though not degradable, e.g. from castor oil

from RRM, bio­ logically degradable

from fossil raw materials, biological degradable, e.g., polyvinyl alcohol

Micro organic origin e.g., polyactic acid

Vegetable origin

Animal origin e.g., chitin

Cellulose

Lignin

Starch

Forecast trend in bioplastics up to 2020 PACKAGING AND FOOD INDUSTRY

AGRICULTURE, HORTICULTURE AND LANDSCAPING

CONSUMER GOODS INDUSTRY

AUTOMOTIVE INDUSTRY

Total market 2005

3.5 mio tons plastic packaging 1.8 mio tons short-life products

230,000 tons total market farming market. Of which approx. 30,000 tons specially suited to substitution

1.8 to 2.7 mio tons plastic consumer goods

Total amount plastic in vehicles 800,000 tons Approx. 400,000 tons plastic as interior vehicle fittings

Bioplastics

2005: < 15,000 t Forecast 2010: 110,000 tons (5 % of short-life plastics) Forecast 2020: 520,000 tons (20 % of short-life plastics)

2005: < 100 tons Forecast 2010: 3,500 tons (10 % specially suited to substitution) Forecast 2020: 130,000 tons (30 % specially suited to substitution)

2005: < 100 tons Forecast 2010: 24,000 tons (1 % of total market) Forecast 2020: 290,000 tons (10 % of total market)

2005: < 10 tons Forecast 2010: 48,000 tons (10 % of vehicle interior fittings) Forecast 2020: 230,000 tons (40 % of vehicle interior fittings)

Bioplastics

2005: < € 45 mio 2010: € 165 mio 2020: € 780 mio

2005: < € 300,000 2010: € 5 mio 2020: € 20 mio

2005: < € 300,000 2010: € 35 mio 2020: € 440 mio

2005: < € 30,000 2010: € 72 mio 2020: € 350 mio

Market growth

2005-2010: > 30 % 2010-2020: approx. 16 %

2005-2010: > 70 % 2010-2020: approx. 15 %

2005-2010: > 160 % 2010-2020: approx. 29 %

2005-2010: > 380 % 2010-2020: approx. 17 %

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Polylactic acid or polylactide (PLA) is one of the most important bio crude plastics in the current sustainability debate, as its properties are comparable with those of PET. Generally speaking, bio crude plastics cannot be used directly, but through compounding are mixed with aggregates and additives to suit their specific purpose. Although the material was discovered as early as the 1930s, it has only recently been produced on a large scale, by NatureWorks ®.

Sustainability aspects  based on renewable resources // can be recycled // can be composted in industrial plants

BIO-based Materials

Bioplastics Based on Polylactic Acid

Material concept and properties

PLA is produced either by fermenting viscous sugar syrup or by the bacterial fermentation of starch or any kind of sugar. The raw material is colorless, shiny, and reminiscent of polystyrene. It is completely biodegradable. The low migration behavior for oxygen or steam makes PLA an interesting alternative for food packaging. A disadvantage is that some polylactides soften at very low temperatures compared with alternative plastics. The mechanical resistance in particular can be improved by adding fibers. PLA surfaces are water-repellent. Depending on its composition the material is either quickly biodegradable or remains stable for several years. Even though PLA is sourced from renewable resources the CO2 footprint for its production is relatively high. It requires a similar level of energy as the manufacture of polypropylene. Compared with the typical mass plastics the production of PLA is still much more cost-intensive; the price is higher than for PET.

Properties similar  property profile to PET // low permeability for gases // water-repellent surface // transparent // relatively low heat-stability of just over 60°C

Cell phone holder made of PLA bioplastics (Source: NatureWorks ®)

PLA food packaging (Source: NatureWorks ®)

PLA foil packaging (Source: FKuR)

Making foil using blow extrusion (Source: FKuR)

Use and processing

PLA blends can be shaped and formed using customary techniques such as injection molding, thermoforming or blow molding (temperatures: 170–210°C). Foils are extruded. Welding or

160 140 120 100 80 60 40 VST B50 [°C] Vicat temperature of various polymers in comparison with conventional plastics

PA6

PL

PET

ABS

PP

PE-HD

Cellulose derivatives

180

Starch blends

PLA

PHAs

PLA blends

200

Biopolyester

Heat-stability of biopolymers PCL

In recent times bioplastics have carved out a niche in particular in the packaging industry e.g., for foils and yogurt cartons. Given that their properties are similar to PET, polylactic acids are expected to increase their stake in the packaging market in the medium term. Moreover, companies in the automobile and entertainment industries are also showing a great interest in using PLA. The fact that it is biodegradable makes the material interesting for use in geo-textiles in the agricultural sector and landscape work. Its use in technical products also seems feasible in the guise of fiber reinforcement. Biocompatible quali­ ties also makes PLA suitable for various medical technology applications – for instance, it can be injected in cosmetic surgery to fill out wrinkles. Its low density is a decisive criterion for its use in lightweight constructions.

sticking is used to produce joints. PLA semifinished products can be processed using the techniques normally applied for processing wood and metal.

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Products

BIO-based Materials

® ®

NatureWorks  -Polymer Since 2002 NatureWorks  has been the world’s largest producer of the bio crude plastic polylactic acid (PLA). The company has developed a method for transforming the sugar occurring naturally in plants into a patented polylactide polymer, which is sold under the brands NatureWorks  -Polymer and Ingeo -fiber.

®

™

®

Ecovio  Ecovio  is the first plastic blend by BASF, which is produced on the basis of renewable resources and is biodegradable. The main constituent with a proportion of 45 % is polylactic acid (PLA). On account of its special properties it is especially suitable for packaging. The material can be printed in eight colors and has a high mechanical resistance. Special modifications can be processed using injection molding and extrusion.

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Bioflex  Bioflex  is a PLA-based co-polyester blend, which, depending on the required property profile, consists almost entirely of renewable resources. It is especially suited for the manufacture of thinwalled foils with high tear resistance, and has similar properties to the classic packaging plastics PE, PP and PS. Bioflex  can be dyed and printed, is approved for contact with foods and its elasticity can be adjusted as required.

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The second heavyweight amongst the bio crude plastics is polyhydroxybutric acid (PHB), as its property profile is similar to that of the widely employed polypropylene (PP). Discovered in France just under 90 years ago, the polyester is produced in almost every living organism, from sugar to starch and oils. It is the most important representative of the polyhydroxyalcanoates (PHA). At present, high production costs hinder the mass deployment of bioplastics. That said, various efforts are being made to lower these costs. In particular companies from the South American sugar industry are getting involved in the industrial production of PHB. According to estimates microbes can transform three kilos of sugar into one kilo of bioplastics.

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Ecogehr  PLA In summer 2008 the GEHR plastics plant became the first manufacturer worldwide of technical semi-finished biopolymer-based products. All the materials based on polylactides are grouped together under the Ecogehr  PLA brand. Depending on the requirements the program includes blends of polylactides with lignin or wooden fibers with various qualities. The materials are physiologically harmless and can be composted or burned.

Semi-finished products made of Ecogehr ®PLA (Source: GEHR Kunststoffwerk)

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Ingeo Salewa was one of the first sports clothing makers to bring to market outdoor clothing made of PLAfibers by NatureWorks  , which are biodegradable. Another advantage over conventional polyester fibers is that they do not simply absorb sweat but transport it away from the body.

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Helmet made using PLA fiber material (Source: NatureWorks ®)

Properties  similar property profile to PP // low oxygen diffusion // UV stability // biocompatible qualities // high fracture susceptibility // PHB melts at temperatures above 130°C Sustainability aspects  based on renewable resources // biodegradable without harmful residues

Bioplastics based on polyhydroxybutric acid

36

Material concept and properties

Polyhydroxybutric acid is a non-transparent biopolymer. In particular its tensile strength is comparable with that of polypropylene. PHB is a thermoplast and melts at a range of 170–180°C, which means it can be processed using the methods customarily employed in the plastics industry. As a material it has constant properties at temperatures between -30 and +120°C. Polyhydroxybutric acid is insoluble in solvents or water and remains stable when exposed to ultraviolet light. It offers very low oxygen diffusion. On account of its biocompatible qualities PHB can be used to produce medical products. A disadvantage compared with polypropylene is its high fracture susceptibility. To enhance its mechanical properties PHB is mixed with other

BIO-based Materials

substances such as cellulose acetate, cork or anorganic materials to produce blends.

mixing proportions PHB blends can also be used as adhesives or hard rubber. PHB can be processed using the techniques typically employed in the plastics industry. These include injection molding and extrusion. Owing to the danger of depolymerization a processing temperature of 195°C should not be exceeded. Very rapid processing speeds can be achieved thanks to the clear transition from fluid to solid. Deforming techniques are difficult given the high fracture susceptibility.

Use and processing

Products

It is expected that polypropylene will be replaced by PHB in several sectors in coming years. Extensive application options are envisaged primarily in the automotive field, in the consumer goods industry, and in packaging. Depending on the

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Biomer  Biomer  thermoplasts are polyesters based on polyhydroxybutric acid. Components made of the material are heat-resistant, waterproof and completely biodegradable. The granules can be processed in conventional machines and transformed into thin-walled components with a complex geometry.

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Natureplast  The French manufacturer specializes in the production of bioplastics such as polylactic and polyhydroxybutric acids. Aside from PLA and PHA, it also produces polymers based on thermoplastic starches (TPS). Missile body made of PHB (Source: Biomer ®)

“Im munostick” diagnostic tool for medical applications made of PHB (Source: Biomer ®)

PCL

Biopolyester

PHAS

PLA (uncoated)

PLA (coated)

PLA blends

PVAL

Starch blends

Cellulose derivates

CH (uncoated)

CH (coated)

PE-LD

PET

PP

PS

EVAL

1400

0.03

303

110

466

5

550

513

7500

35

3650

35

1250

1118

1

[cm³/m²·d·bar]

1192

Oxygen permeability of biopolymers in accordance with DIN 53380, ISO 15105-2 at 23°C, 0-5 % relative humidity, film thickness: 50 μm

7,500

6,000

4,500

3,000

1,500

0

Oxygen permeability of various poly mers in comparison with various conventional forms of packaging

Polymers based on thermoplastic starch (TPS) make up the lion’s share (just under 80%) of global bioplastics production. Sourced from corn, grains and potatoes, they are available everywhere and good value for money.

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Properties  ability to absorb liquids // good value for money // mechanical qualities between LDPE and PS // excellent gas barrier properties // energy-efficient production Sustainability aspects  based on renewable resources // excellent biodegradable quality // energy-efficient production

BIO-based Materials

Material concept and properties

Since thermoplastic starch exhibits the unfavorable property of absorbing water (hygroscopy), it is just one component in plastics production. The other is a biodegradable polymer such as polyvinyl alcohol or polyester, which makes up the waterinsoluble part of the plastic blend. The respective composition of the mixture is developed according to the specific application. This means that TPS blends have a broad applications spectrum. Natural glycerin can be added to increase flexibility during processing. Use and processing

The ability of thermoplastic starch to absorb liquid substances is exploited primarily in the pharmaceuticals industry for the production of medication capsules. Other possible applications lie in those fields typical for bioplastics, namely the packaging industry and in hygiene articles. Specific products include disposable cutlery, packaging foils, yogurt cartons, plant pots, plastic bags, and coated cardboard. TPS blends can be injection molded or extruded just like conventional plastics (processing temperature: 120–180°C). For printing and coating those techniques commonly used in the plastics industry can be employed. Products

Bioplastics based on thermoplastic starch ®

Biopar  This naturally degradable thermoplastic is made entirely from potato starch. Its properties make it a competitor to polyethylene, polypropylene and PVC. Thanks to its particular barrier properties for gases it is especially suited to packaging. It can be worked on foil blow and injection molding systems. Its production and processing require just 1/3rd of the energy needed for conventional plastics.

extremely good permeability for steam and offers excellent barrier qualities against oxygen and carbon dioxide. This makes the bioplastic ideal as an external packaging for food; it is also foamed into dishes for fast-food packaging or into watersoluble foils. Since it comes as a granulate it can either be used on its own or as a single component blended with other polymers.

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BioplastTPS  The French company Bioplast specializes in the development of thermoplastic plastics made of potato starch. They are edible, water-soluble and 100% biodegradable. BioplastTPS  also exhibits

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Biomax  TPS The developers at DuPont in Neu-Isenburg are spearheading the employment of bioplastics in technical constructions. Biomax  TPS, a thermoplastic starch based on bio resources, is suited to packaging, the manufacture of containers, and other molds for plastic injection molding. Extruded foils are also available.

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Sorona  Sorona  is a plaster based on cornstarch, whose properties resemble those of the technical plastic PBT. Alongside high sturdiness and rigidity it is first and foremost the improved surface quality, the high shine, and excellent dimension stability that make the material attractive for a great many industrial and consumer goods, not to mention electronic components.

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Foil packaging made of Biopar ®

Injection-molded parts made of Biomax ® TPS

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Cellulose is the most common organic compound in the world since it is found in the cell walls of every plant. Like starch it is a natural biopolymer that is ideally suited to producing thermoplastic bioplastics for translucent components. The most important examples are cellulose acetate (CA) and cellulose triacetate (CTA).

Properties  good mechanical properties (like PS) // optical transparency // self-polishing properties // good thermal resistance // normally requires a softener for processing Sustainability aspects  based on renewable resources // can be recycled but not bio­ degradable

BIO-based Materials

Material concept and properties

Plastics based on cellulose can achieve light permeability of up to 90%. Cellulose acetate was first processed as long as 90 years ago. Thanks to their self-polishing surface, silky sheen and excellent dyeing quality, cellulose plastics have always been potentially attractive for the manufacture of a large range of products. However, they must not come into contact with food. Mixing with other plastics can produce polymer blends with diverse properties.

Bioplastics based on cellulose

Use and processing

Typical application areas for cellulose acetate: the grips of writing utensils, umbrella handles, spectacle frames, cigarette filters, diving goggles, vehicle steering wheel covers, lampshades, toothbrush handles, toys and tool handles. As they do not catch fire easily they can be used in interesting safety applications. CA foils occur in flat screen monitors and displays. In the field of textiles they replace natural silk. Since cellulose molecules are very stiff, the extent to which they can be processed depends on the amount of softener added. Fundamentally, CA and CAB can be very well injection molded and extruded. The processing temperatures lie between 190 and 240°C. Cellulose ether surfaces can be printed, varnished or metalized. Products

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Moniflex  Insulating panels made of cellulose were used for the first time as long as over 60 years ago, as insulation in Scandinavian railroad carriages. Since then the lightweight building material has formed the core of formwork elements in carriage constructions. Moniflex  is translucent, bend-resistant, long-lasting and biodegradable. It can be worked using the customary techniques.

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Zelfo  This material is made completely from cellulose fibers of plant origin (e.g., hemp, flax, waste paper). It is transformed into a pliable mass without the addition of water or adhesives and can then be injection molded, extruded or compression molded. The material is already used to

Comparative moisture absorption [cm³/m²·d·bar]

25 % 20 % 15 % 10 % 5 % 0 % Polyester

Cotton

manufacture musical instruments, luminaires, furniture and furnishing items.

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Biograde  This thermoplastic bioplastic was developed especially for injection molding and extrusion plants. It contains a high proportion of cellulose, exhibits excellent shape retention under heat up to a temperature of 122°C and has similar properties to polystyrene. It can also come into contact with food. AgriPlast BW In Brensbach in the Odenwald region of Germany, Biowert Industrie GmbH operates a grass refining plant, which is based on the principles of “green bio-refinery” and transforms moist biomass containing fibers to a composite granulate, without the use of chemical additives or solvents. Some 50–75% of the granulate is cellulose fibers, 25–50% is polyethylene or polypropylene. Components made of AgriPlast BW are 20% lighter than

Tencel®

Wool

their counterparts in PP. The firm also supplies AgriCell BM, an insulating material based on natural biomass.

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Tencel  Tencel  is a textile fiber based on cellulose with extremely strong moisture absorption for ideal climatic conditions. This hydrophile quality results from an innovative nanostructure, which enables Tencel  textiles to absorb some 50% more moisture than comparable cotton products. The cellulose stems from Eucalyptus timber.

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Arboform  The thermoplastic bioplastic Arboform  was developed as early as 1998 and consists largely of lignin and cellulose. The latter stems from waste from the paper industry. During production it is blended with other natural fibers such as hemp, flax, Chinese silver grass, as well as natural additives. The bioplastic can be worked using injection molding or extrusion and can be recycled.

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39 BIO-based Materials

Containers made of Arboblend ® containing cellulose (Source: Tecnaro)

“Liga” chair made of Zelfo ® (Source: Elise Gabriel & TheGreenFactory)

Storage boxes made of cellulose plastics (Source: Biowert)

Beakers made of Biograde ® cellulose plastics (Source: Biowert)

Lampshade made of Zelfo® (Source: TheGreenFactory)

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Aside from starch, cellulose and lignin, vegetable oils can also provide the raw material for bioplastics and enable the bio-based production of polyamides for technical products, resins for fiber compounds or foams.

BIO-based Materials

Material concepts and use

Bio-based polyamides Polyamides are among the classic thermoplastic plastics that thanks to their properties lend themselves to various applications in the technical field. In the manufacture of PA 6.10 sebacic acid is employed, for the production of which castor oil can also be used. The latter is sourced from the seeds of the Ricinus Communis tree, and its use does not compete with the cultivation of food. Bio-based polyamides, whose production principle has been known for 50 years, can compete with petroleumbased polyamides. Seen across their entire lifecycle they have a more favorable CO2 footprint than comparable petrochemical polyamides. Bio-based soft foams The lion’s share of soft foams is made using the combined system. Polyols and isocyanates form the basis, to which additives and water are added and made to react. At the end of a conveyor belt the foaming mixture is cut into blocks and shaped. Some manufacturers have succeeded in producing polyol based on castor oil, which substantially reduces the share of petrochemicals in foam manufacture. Soya oil and rapeseed oil can also be used in place of castor oil. Mattresses made of soya foam are now available on the market.

Sustainability aspects  based on renewable resources // not always biodegradable

Bioplastics based on vegetable oils resources. Intensive research is currently being conducted into the development of these biobased resins. Products

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Lupranol  Lupranol  is the brand name of a polyol for the manufacture of soft foams, which was brought to market in 2008 and has a 31% proportion of viscous castor oil. The use of rapeseed, sunflower or olive oil to make polyetheroles failed largely because of the undesired odor and emission levels.

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Vestamid  Terra The polymers consist largely of plant fatty acids, the main source being castor oil. Vestamid  Terra DS is a completely bio-based polyamide 1010, its qualities putting it between long-chain high-

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Bio-based resins The monomers needed to produce polyester resins can also be manufactured using renewable

performance polyamides such as PA 12 and PA 1212, and the short-chain standard polyamides PA 6 and PA 66. This makes is primarily suitable for the manufacture of fiber glass-reinforced masses. In the next few years further polyamides based on palm olive and rapeseed oil are due to be developed.

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Envirez  Envirez is the brand name of the first unsaturated polyester resin on the market that contains a 25 % proportion of renewable resources such as soya oil (13 %) and grain-based ethanol (12 %). It offers the same performance parameters as synthetic resins and can be worked in conventional presses. Application areas are in agriculture construction, the transport industry, and ship construction. The material was enhanced as regards its properties for masses ready for pressing, wound fiber components and pultrusion.

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Akromid  S This is a polyamide 6.10, based to 60 % on castor oil, whose technical properties were optimized such that it can be used in automobile production.

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Grainfield (Source: Ashland)

Foam made of castor oil (Source: BASF/Elastogran)

Vestamid ® Terra pellets (Source: Evonik)

Rubex  NaWaRo These foams consist to a large extent of raw materials sourced from vegetable oils. The cultivation of both rapeseed oil and sunflowers is suited to this end. The foams are environmentally friendly and not hazardous to health.

After cellulose, lignin is the second most common biopolymer found in nature. It is responsible for the lignifying and stiffening effect in the outer layer of every plant cell. Up to 30% of a tree, for example, consists of this natural material.

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Properties  good mechanical properties // high degree of rigidity // brownish coloring // duroplastic qualities Sustainability aspects  derived from renewable raw materials // lignin replaces synthetic adhesive in the vibration welding process

BIO-based Materials

Material concept and properties

For industrial use lignin is extracted in a boiling process from wood shavings and fibers and, for example, blended with methanol and hydrochloric acid to form a resin-like substance. This can then be incorporated in a polymer blend or made directly into a duroplastic. Blends with lignin as a component have good mechanical properties and a high degree of rigidity. Lignin is brownish in color.

Lignin-based bioplastics

Use and processing

Nowadays, lignin-based plastics are used to make houses, vehicle dashboards, buttons and toys, etc. The processing qualities are comparable to those of wood. In recent years a vibration welding

Bagasse

Corn spindles

Wheat straw

Beech

Birch

Coniferous wood

Proportion of lignin in vegetable biomass

Snowboard manufactured by vibration welding (Source: Berner Fachhochschule, Architektur, Holz und Bau)

Pore structure as a result of vibration welding of composite wooden surfaces (Source: Berner Fachhochschule, Architektur, Holz und Bau)

process was developed in Switzerland, in which two surfaces that are to be joined are rubbed together at a frequency of 100 Hz under pressure such that the lignin in the wood structure melts at temperatures between 180–230°C. The lignin

then functions as a natural adhesive in the pores of the wooden components, which subsequently joins these securely together as it cools. The adhesion is sufficiently rigid for industrially produced furniture and panels.

40 % 35 % 30 % 25 % 20 % 15 % 10 % 5 % 16-21

15-19

18-25

22-23

19-20

27-32

0 %

Just as energy producers are discovering algae as a source of hydrogen, the plastics industry has also recognized the advantages of this renewable material.

Alginsulate foam (Source: Verpackungszentrum Graz)

Properties  qualities such as EPS // no pollutants during production // stable under water // mold-resistant Sustainability aspects  based on renewable raw materials // no pollutants during production process // can be naturally composted // recyclable

Algae-based bioplastics

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Material concept and properties

Researchers at the Technical University in Graz recently succeeded in producing an alginsulate foam from fast-growing algae (up to one meter growth per day) which, considering its property profile, could potentially replace expanded polystyrene. It is notable that no pollutants are formed during production and that only air is used for the foaming process. After use the finished product can be composted or recycled with waste paper, but does not dissolve under water. Nor is it susceptible to consumption by insects or to mold or fungi.

BIO-based Materials

Laboratory sample made of Alginsulate (Source: Verpackungszentrum Graz)

In addition to bioplastics derived from microorganisms (e.g., PLA, PHB) and those derived from plants (e.g., lignin, cellulose) the third main source of bioplastic production is animal constituents. In this context the most commonly discussed source material is chitin.

Use and processing

Alginsulate foam materials can potentially be used wherever environmentally harmful EPS is still used today, e.g., transport packing, in the fast-food industry, as heat insulation or for car interiors. The natural and flame-resistant properties also make the material an interesting option for the building industry. Compared with conventional foams, alginsulate is expensive to procure. However, given the entire product life cycle and the possibility of easy disposal, the material is said to have sound market potential as a replacement for polystyrene. Alginsulate foam materials can be cut with conventional processing techniques and joined with adhesive. At present research is being conducted into improving the working properties with additives.

Properties  styptic // antibacterial // soluble in water and alkaline solutions // oxygen barrier Sustainability aspects  based on natural raw materials // biodegradable

Material concept and properties

Like cellulose, chitin is a polysaccharide. It is the main component in the skeletons of spiders and crabs and also exists in the cell walls of fungi. It is extracted, for example, by grinding dried crab shells then washing these in caustic soda. Chitosan is then formed in a saponification process. Depending on the molecular structure, it exhibits interesting solubility characteristics in water and caustic soda, which makes the resulting styptic and antibacterial properties suitable for potential use in medical products and biotechnology. It also acts as an oxygen barrier.

HemCon ® Bandages with antibacterial effect (Source: HemCon ®)

Bioplastics from animal sources Use and processing

Although chitin exhibits a very interesting range of properties, the application options are comparatively straightforward in comparison to cellulose and lignin. With its fat-binding qualities, chitosan derived from chitin is used for filtration in sewage plants as well as in the pharmaceutical industry. Other applications are wound dressings, toothpaste, biodegradable surgical thread, wood preservative and binding or smoothing agents for the paper industry. Chitosan dissolves under the influence of ascetic acid and can subsequently, for example, be poured to create a film. It can also be processed into foams and fibers.

A process is currently being developed, which, in a few years time, will make it possible to industrially produce polymethyl methacrylate (which goes by the trade name “Plexiglas”) from natural raw materials such as sugar, alcohol and fatty acid. In 2008 the inventor, Thore Rohwerder, was one of three candidates nominated for the European Evonik Research Prize.

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Sustainability aspects  based on natural raw materials // less energy consumption for production // less waste

BIO-based Materials

Material concept and properties

PMMA is one of the classic artificial materials with properties akin to glass and was launched on the market by Otto Röhm as early as 1933. It is based on polymerizing methyl methacrylate (MMA). Scientists have now discovered an enzyme in a bacterial strain, which can serve the biotechnological production of a precursor to MMA. In collaboration with Evonik Röhm GmbH, researchers are currently attempting to produce acrylic glass from renewable materials for the first time. This is intended to be as clear as glass and not splinter, that is, to boast the same properties as traditional “acrylic glass”, which has been in use for about 80 years.

Acrylic glass derived from sugar

use

Plans are currently being drawn up for the operation of a pilot plant in the coming years. The long-term aim is to produce up to 10% of current demand for MMA by biotechnological means. Compared with the previous chemical production method, the new process is more environmentally friendly, requiring less energy and reducing waste products.

Natural rubber, which the Maya civilization used to make balls for the traditional game of pelota, a sort of early basketball, is extracted from the sap of the rubber tree (latex). The ball presumably symbolized the sun, and its flight the path through the celestial sphere, which was to be never-ending. Consequently, during the game the ball was not allowed to touch the ground. If a player allowed this to happen his team lost. A special property of the rubber ball was its enormous bounce and elasticity. Material concept and properties

Natural rubber consists of natural caoutchouc, water and sulfur. It has outstanding elastic properties. Strips made with it can sometimes be stretched to ten times their original length. The natural product is also very resilient, which is why it is used in almost all rubber blends for tires.

Microscope photos of bacterial strain discovered (Source: The Helmholtz Centre for Environment Research (UFZ))

Properties  high degree of elasticity // amber color // sticky when wet // rubber tends to age and become brittle // susceptible to fungi Sustainability aspects  based on renewable raw materials // biodegradable

Natural rubber

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Natural caoutchouc is used in almost 40% of all industrial rubber production today. As a resilient fungus currently affects rubber trees, scientists are working on an alternative source. It has been discovered that the milk of dandelions has similar properties to latex, though the fact that it polymerizes as soon as it is extracted is problematic. Scientists have now localized an enzyme that triggers this effect. Modifying the plant through gene technology promises to make the latex milk usable for industrial applications and to considerably increase the amount of naturally produced milk.

BIO-based Materials

Use

Natural elastomers are used in balloons, condoms, gloves and textiles as well as in technical products such as tires, rubber springs, membranes, engine mountings and seals. Natural rubber is found in flooring and is processed into seals, hoses and cable coating. When wet, natural rubber is sticky and suitable as an adhesive substance.

Natural latex baby’s comforter

Properties  thermoplastic // even property distribution // high degree of rigidity and bending strength // good moisture resistance // very stable // acoustic qualities Sustainability aspects  based on re­ newable raw materials // substitute for tropical woods in outdoor use // crude oil-free matrix materials are biodegradable

Wood polymer composites (WPC)

Sourcing natural caoutchouc in Thailand

Internationally the term “wood plastic composites” (WPC) has established itself as a description of wood-polymer composites. In German-speaking countries, wood polymer composites are often referred to as “liquid wood”, as WPCs can be processed in a thermoplastic process, that is, melted and shaped three-dimensionally.

Material concept and properties

WPCs consist of wood fibers, a plastic matrix (PP, PE or PLA) and various additives. The proportion of wood fiber is generally between 50–90%. As the latter has no fiber direction in the subsequently shaped product, liquid wood has an even property distribution. The positive qualities of WPC are its low shrinkage and high degree of rigidity, the low thermal expansion and high resistance to moisture. These properties are particularly desirable in the manufacture of precision components, which are not or at least not easily made of wood. Use and processing

WPC shelving system (Source: Mehrwerk Designlabor)

The use of WPCs is of interest whenever complex geometrical shapes with a wooden appearance are needed. Typical products are casings for electronic devices, handles, furniture, outdoor ground surfaces, bio-urns, fashion accessories and building components for vehicle interiors. In building interiors they are used for skirting boards and shelving systems. Wood polymer materials can be processed using typical plastic processing techniques such as injection molding, extrusion,

compression molding and thermoforming. Due to the wood content the maximum processing temperature should not exceed 200°C.

45

Products

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Fasal  Fasal  was developed at the Institute for Natural Materials Technology in Tulln with a view to manufacturing products with a wood-like appearance that are based on renewable raw materials such as wood and corn, and has been optimized for the injection molding process. Products made from Fasal  have very hard surfaces, a wood-like appearance, high bending strength and are very stable. The high density gives the material special acoustic qualities. The main applications for Fasal  are biodegradable packaging, toys, musical instruments and car interiors.

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BIO-based Materials

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Megawood  Megawood  is the brand name for a material composed of up to 75% renewable raw materials (wood particles) and about 25% polymers and additives. It is mold resistant, extremely robust and is thus suitable for barefoot decking for patios, balconies and gardens. The material requires little maintenance. Only timber from regional sources is used in its manufacture.

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Kupilka  In Finland this is the name given to multipurpose vessels made from 50% wooden fiber and 50% polymers. Compared with plastic, Kupilka products are more heat resistant (-30 to +100°C); they are also more hygienic and stable than wood. The products can be shredded and injection molded again. Personal laser inscriptions are also possible.

Shoe with heel made of liquid wood (Source: Tecnaro)

WPC patio decking (Source: Kovalex ®)

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Fibrolon  This name embraces a range of WPC products. These can be injection molded, compression molded or extruded. There are versions with wood-like rigidity, mechanical stability and heat resistance. The wooden fibers come from European softwood timber. Composites based on a PLA matrix are 100% biodegradable. Components made of liquid wood (Source: Tecnaro)

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Werzalit  Werzalit  consists of wood particles that are firmly integrated in a matrix. In the manufacturing process the plastic is first melted, after which the wood particles are added and subsequently pressed into shape. There are many semi-finished products made of Werzalit  already on the market.

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Other WPC brands include Xylomer  , Ecogehr  WPC, Kovalex  , or Thermofix  .

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Fibrowood automobile interior featuring wood fiber mats with acrylic resin binder (Source: Johnson Controls)

In order to avoid using valuable tropical woods and thus felling rain forests, techniques have been developed in recent years to make the wood from coconut palm plantations suitable for the furniture industry and for flooring (e.g., coconut wood project).

46 BIO-based Materials

Properties  very hard outer layer density > 800 kg/m³ // structure without growth rings // dimensional stability // high bending strength

Sustainability aspects  auf Basis nachwachsender Rohstoffe // Verhindern der Abholzung tropischer Regenwälder

Material concept and properties

Coconut wood has no annual rings. It is characterized by its spotted structure from which the Dutch manufacturer Kokoshout derived the name “Cocodots”. As the wood is significantly harder at the periphery of the trunk (outer 5 cm) than on the inside, it is primarily this wood that is used for material production. Coconut wood only shrinks and swells minimally and is harder than oak. Coconut wood composites consist of a 12–18 mm thick MDF-core, to which coconut wood is applied.

Coconut-wood composites

use and processing

The material composites are made into furniture surfaces and are used in interior design, for example for parquet flooring, lamps, vases, dishes and accessories. Wall panels have also been developed so coconut wood composites can now be used for complete interiors. With its interesting surface structure coconut wood is also popular for fashion accessories. Conventional timber processing technology can be used for coconut wood, and oils are used to create an especially intense color.

Wall made of coconut wood (Source: Kokoshout)

Products

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Cocodots  The wood composite Cocodots  comprises 16 x 22.5 cm pieces of coconut wood applied to wood fiberboard or plywood boards. The dotted structure makes the optically appealing material interesting for high-end hotel and boat finishing. It is particularly suitable for tabletops and flooring. As the coconut wood absorbs moisture from the environment, it is important to keep the relative humidity constant at a level of between 50–70%. Large fluctuations may cause damage. Combined with wooden panel material Cocodots  has a high bending strength and good dimensional stability.

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Interior fittings featuring coconut mosaics (Source: Decor Pietra)

Wall featuring coconut mosaics (Source: Decor Pietra)

Kitchenette featuring coconut mosaics (Source: Decor Pietra)

Piece of furniture featuring coconut mosaics (Source: Decor Pietra)

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Coconut Tiles Given their unique aesthetic appeal, the coconut mosaics manufactured by Ekobe in Brazil are particularly suitable for decoratively covering walls and furniture. Use as flooring is recommendable only for floors that have to withstand light to moderate traffic. It should also be noted that coconut mosaics should not be permanently exposed to water, though treating the surface with oil or wax can reduce damage through moisture.

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Given the fact that it grows very quickly and is an extremely light building material, bamboo is immensely important in many regions of the world. Its high level of vibration absorption is the reason it has been used in a series of design studies for bicycles – as an alternative to carbon fiber-reinforced plastics or aluminum.

high elasticity // very high tensile strength // 25 % harder density 600-800 kg/m³ // to moisture damage

Sustainability aspects  renewable material // biodegradable // light construction potential with high durability and stability

BIO-based Materials

Material concept and properties

Bamboo can grow to a height of nearly 40 meters with stem circumferences of up to half a meter. The wood is 25% harder than oak and more durable than hardwoods. The hollow interior makes the material highly elastic and light (density 600–800 kg/m3). The extreme bending strength and a tensile strength similar to structural steel makes bamboo an obvious choice as an earthquake-resistant building material. It can, however, splinter. When used outside it is also necessary to protect this natural product from the effects of moisture and to make it resistant to insect damage and fungal decay. Bamboo has no resin or tannic acid, so it is well suited to paint and oil adhesion.

Properties  bending and than oak // susceptible

Bamboo Products

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Native  bamboo Native  bamboo is a new type of fiber made by architectural textile manufacturer GKD in Düren. Woven steel is combined with natural material in a purist look. The material can be used both indoors and outdoors. The special construction with variable density and cable pitch can be adjusted to the particular application.

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Moso  Moso  is a brand name of flooring, floorboards and laminated bamboo boards. Applications range from seating and tabletops to bathtubs and wooden inline skates.

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Use and processing

Bamboo is traditionally used in the building industry for scaffolding, furniture construction, household goods, furniture and flooring. It is a component in wooden materials such as OSB and rod panel and, if blended with resin, makes hardwearing parquet and flooring. Comparatively high strength levels can be achieved. Bamboo fiber is also used in composite materials such as WPC, fiber-reinforced concrete and bioplastics. While the use of bamboo in architecture is declining bicycle makers are currently investigating the potential of this renewable raw material. The canes are smoked and heat-treated to dry them. Panels are joined by means of hemp fibers embedded in epoxy resin.

Bamboo tube bicycle frame (Source: Craig Calfee)

Construction solution using bamboo cane (Source: Conbam ®)

Bamboo cane in cross-section (Source: Moso ®)

Public bench made of bamboo cane (Source: Conbam ®)

Ceiling construction using bamboo at Madrid Airport (Source: Moso ®)

Wood is a natural material whose properties change according to environmental influences. When exposed to moisture, certain tropical woods in particular experience less swelling than varieties of European wood such that – taking sustainability aspects into consideration, and thus the protection of tropical forests – increasing the quality of lower-quality wood to make it suitable for outdoor use is gaining in importance. Material concept and properties

One possible technique for positively influencing the effects of swelling and shrinking is heat treatment in hot oil (170–250°C). As a result of this treatment, which takes 24–48 hours, the cell structure changes to such an extent that water absorption and the moisture content equilibrium are significantly lowered. Volatile substances such as resin are extracted and the proportion of hemicellulose and lignin reduced. The swelling behavior of heat-treated wood is reduced by about 50%. The wood’s color also becomes significantly darker. Moreover, bacteria and wood-decomposing fungi lose their food source, while acoustic properties improve. Charring the uppermost layers at still higher temperatures creates a natural protection against insect damage and rotting. In recent years the traditional technique of charring has been rediscovered in architecture. Another possibility for preparing lower-quality woods for outdoor use is acetylation. This process involves less durable woods being subjected to heat and pressure and made to react with acetic anhydride. This process considerably reduces the water absorption rate of wood, making it particularly suitable for outdoor applications. With the aim of achieving a homogenous dark color, different types of wood can be subjected to steaming (temperature approx. 100°C). This process changes the wood properties but not significantly. A well-known example is steamed red beech.

48 BIO-based Materials

Sustainability place tropical in procurement reducing crack

aspects  local species rewood // less energy consumed // increased durability by formation

Heat-treated natural woods

Müritzeum - facade of charred larch boards (Source: Müritzeum GmbH)

Use and processing

In recent years both heat-modified and acetylated types of wood have been competing with tropical woods such as teak and mahogany, which are commonly used for outdoor and wet areas. They can be found in garden and land­ scape architecture and spa areas, and as facade cladding, solid timber flooring, toys, playground equipment and decking. Treated wood can be processed with normal wood processing techniques. products

Patio surface featuring heat-treated natural wood (Source: Menz Holz)

Properties  lower water absorption // very high dimensional stability // dark coloring // fungal resistance // good acoustic properties

OHT wood At Menz Holz, lower-quality woods such as ash or elm are submerged in a rapeseed oil bath at a temperature of 220°C, as part of a multi-phase upgrading process lasting some 22 hours. The wood becomes significantly more durable and darkens in color like tropical wood. No chemical additives or biocides are used in the process. The

used oil is then utilized for heat production, and the process boasts a sound ecological balance.

®

Admonter  One example of the use of wood for flooring is Admonter  , which is made from local timber with no chemical additives, thereby making a contribution to sustainable material use.

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® ®

Accoya  The resistance of Accoya  Holz is comparable with that of almost all tropical woods. As a result of an acetylation process, the swelling properties are reduced, making Accoya  Holz considerably more dimensionally stable. As such it is also suitable for architectural applications.

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Other heat-treated natural woods include: ThermoWood  , Thermoholz Baladur  , Firstwood 

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49 BIO-based Materials

Dark floor made of heat-treated natural wood (Source: Admonter ®)

Construction technique for heat-treated natural wood (Source: Menz Holz)

Facade made of Thermowood ® (Source: Römermuseum Osterburken)

Thermo-mechanical compaction has proved its worth in increasing the mechanical properties of solid wood for technical applications. At temperatures of 140°C and under 5 MPa of pressure, the strength of domestic coniferous wood can be considerably increased, such that it can be used for a wide range of load-bearing functions.

Material concept and properties

Mechanical compression takes place at temperatures above the softening point of lignin. In the process the wood, which has a porous proportion of 60%, is compacted to less than half its original volume. This serves to increase its strength and rigidity considerably. Heating it to a temperature of over 200°C also causes an increase in its biological resistance. The process sees wood as a cellular material. The compression takes place without damage to the cell structure, and can be reversed and set. The principle is primarily used in the manufacture of shaped wooden tubes dimensions, close to those of load-bearing structures. Malleable profiles of single-axis compacted wood are produced, the shape of which is created by cross bending. The amount of material saved compared with circular timber is around 80%. Waste can be avoided almost entirely.

Bridge made of heat-treated wood (Source: Enno Roggemann GmbH)

Properties  clearly increased rigidity // high density // 80 % less material used for shaped wooden tubes // very weather resistant Sustainability aspects  saves materials compared with round wood // requires less energy than the manufacture of wood-fiber materials

Thermo-hygro-mechanically compacted wood (THM) Process for manufacturing formed wooden profiles from compacted rectangular and rounded timber

50 BIO-based Materials

Use and processing

Thermo-hygro-mechanically shaped wooden profiles can be used in the building industry and architecture, in lightweight and model construction, as well as in the packaging industry. To improve shearing stress and transverse load stress and increase weather resistance compounds can be made in conjunction with fiber reinforced plastics.

Round wood profile made of thermo-hygromechanically shaped wood (Source: Prof. Peer Haller; photo: ddp N. Millauer)

Shaped wooden tubes for architectural applications (Source: Rolf Disch Solar­ Architektur, Prof. Peer Haller)

In 2007 a new composite material based on natural cork was presented to the public – a material that has new application potential for the building industry, furniture manufacture, and sport and medical devices.

Properties  interesting tactile quality // adjustable flexibility // noise and vibration-reducing // thermoplastic processing qualities // water-impermeable // rot-resistant Sustainability aspects  based on renewable raw materials // degradable if a crude oil-free matrix product used // can be recycled

Material concept and properties

CPCs consist of cork particles measuring 0.5–2 mm, fixed in a compound of polyvinyl acetate, TPE or soft PVC. The thermoplastic bonding material lends the CPC interesting properties and a special tactile quality. Flexibility can be adjusted from stiff to highly flexible without having to use softening agents. The new material group combines the water-permeable qualities of natural cork with the positive processing qualities of thermoplastics. Depending on the application, CPCs contain between 20–80% cork. The natural material is 100% waterproof, rot-resistant and very well suited to indoor and outdoor use. Cork polymer composites can be recycled.

Cork polymer composites (CPC) Cork components

Use and processing

The outstanding noise and vibration-reducing properties make CPC biocomposites suitable for a wide range of sports articles and orthopedic products. An increasing number of designers are also coming to appreciate the water-repellent properties of cork and to use it for furniture, lamps and vases. Innovative use of CPC for panels and wash basins is of particular interest. Other typical

suberin

vanillin, tannic acid cerin

cellulose

water

lignin

products are bicycle and ski pole handles, sport mats, shoe parts and innersoles. CPC granulate can be processed in extrusion or injection molding plants. It can be thermally shaped, but other typical wood-processing methods can also be used. Products

51 BIO-based Materials

®

Lifocork  The cork biocomposite Lifocork® consists of cork particles and a thermoplastic such as soft PVC, TPU or TPE. Apart from those already mentioned, fields of application include furniture, decorative objects and household articles. Coextrudates can also be made with PP and PE. These same combinations also apply to dual-component injection molding. In its foamed version it can be used as the cushioning component in orthopedic products.

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Vinnex  To manufacture biocomposites with cork particles a thermoplastic compound is required, in which the cork particles are firmly integrated. Vinnex® is a polyvinyl, acetate-based, free-flowing powder that can be thermo-plastically processed, and also clings superbly to natural fibers.

Flexible CPC mats (Source: Pallmann Maschinenfabrik)

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Amorim  The Portuguese company, which is the largest cork product manufacturer in the world, not only features classical cork applications in its program but also products for technologically sophisticated applications in the automobile, space travel, shipbuilding and building industries.

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Thermofix  This cork polymer consists of 30% cork particles, 30% coconut and 40% PVA. The material can be shaped very effectively thermally in presses. It is mainly used for wall panels and flooring.

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Subertres  Subertres  is an injection-molded cork that is suitable for numerous applications in the building industry, the automobile industry and in shipbuilding. The cork particles are mixed with acrylic resin, plant fats and water, and applied to roofs, patios and facades for isolation purposes. It has good adhesive qualities. The material dries in 8–48 hours.

®

Helmet made of cork (Source: Kévin Goupil)

CPC suitcase (Source: Müller Kunststoffe GmbH)

Lifocork ® panels

CPC secateurs (Source: Müller Kunststoffe GmbH)

52 BIO-based Materials

Cork lampshade (Source: Tiago da Costa)

In addition to wood and cork, other plant particles and fibers such as almond and nut shells can be used to make materials sufficiently rigid for furniture production. Material concept and properties

The name “Maderón” describes a recyclable mixture of ground almond shells – which like wood consist predominantly of cellulose and lignin – and a biodegradable resin matrix. The mass is processed to the desired shape in molding presses. High-strength, durable components with a homogenous surface and airtight structure and no added poisonous substances or formaldehydes are produced. Almond polymer composites with a crude oil-free matrix material can be easily composted and recycled.

Properties  high-strength and durable // homogenous surface structure // airtight // thermoplastic processing properties // compostable // recyclable Sustainability aspects  replaces wood with plant waste products // raw material grows more quickly than wood // biodegradable with crude oil-free resin matrix

Almond polymer composites (APC)

Use and processing

“Maderón” is used in furniture manufacture and as a coating material in interior design. As it is airtight, it was developed initially for the high-quality surface structure of coffins, which are intended to subsequently decompose in the earth. Almond polymer composites can be processed with methods typically used in the timber industry such as sawing, milling and gluing. The fine structure can be individually coated in screen and pad printing.

Almond shells

53 BIO-based Materials

APC coffin (Source: Maderón)

They have such unique names as Chlorophyta, Phaeophyta, Rhodophyta, Cyanobacteria, Pyrrhophyta and Haptophyta and are divided into various groups according to their color. We are talking here about algae which can be found in warm and cold waters around the planet – in microscopically small structures (e.g., diatom) to meter-long seaweed (e.g., brown algae). Of the around 80,000 known species almost 200 are used industrially. Although in Central Europe algae are seldom used as edible plants, given their numerous valuable nutrients they often serve as food, animal fodder and cosmetics, primarily in Asia. Some 3.5 million tons are produced worldwide. This could soon change, as algae have been discovered to have a natural reinforcing effect in composite materials.

Properties  rapid growth // available worldwide // aesthetic transparency // flame-retarding properties Sustainability aspects  replaces con­ ventional reinforcing fibers // decomposes when natural resin matrix is used

Algae-based materials

Material concept and properties

Algae are available worldwide and are relatively easy to cultivate. The natural transparency of the fiber material and its special aesthetic appeal make it a popular choice in the design industry. Longfiber algae (e.g., laminaria algae) are boiled and processed while wet. A resin system is added to the algae, which are then shaped using a shaping tool. When incorporated in surface materials they produce special light effects. USE

In the design field long-fiber algae are commonly processed for design applications, for building containers and wall panels for interior design. There is also application potential in art.

Algae-reinforced objects (Source: Mandy den Elzen)

54

Properties  properties akin to polystyrene // heat-insulating // shock-absorbent Sustainability aspects  based on natural waste material // energy-efficient manufacturing process // compostable

BIO-based Materials

Fungus-based materials

While ecological materials already focus on the use of natural fibers as a reinforcing material and natural materials in composites, a number of researchers and manufacturers are now working on production processes that enable materials to be grown organically. Fungal species come into play here, for example those able to solidly bind organic waste materials. Crude oil is not required. Material concept and properties

The organic manufacturing process is based on the cellulose found in natural waste products such as the husks of rice and wheat, as well as on lignin as a binding matrix material. A new process utilizes the growth principles of the thread-shaped myzelium of fungi, which in nature usually colonizes on solid substrates such as wood, soil and organic waste, to produce hard foams naturally. The fungi form a network of microscopically small threads, which solidly binds the various organic waste materials. The growth process, which takes place in the dark, is completed by dehydrating and drying the material in an oven at a temperature of over 43°C. In the production process ten times less energy is consumed compared with the manufacture of synthetic foam materials. The material can be naturally composted after use. use

With shock-absorbent properties similar to polystyrene, it has mostly been used so far as biodegradable packaging material under brands such as EcoCradle while the special aesthetic and surface structure makes it particularly interesting also for use in interior design and art objects.

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Fungi-based packaging material (Source: ecovative design)

With its excellent heat insulation properties it can be used in composite structures for the building industry. (Source: ecovative design)

Fungus-based hard foam objet d’art (Source: ecovative design)

Improving material properties by adding fiber is a process that has been known for a long time. Although to date, primarily glass, aramide and carbon fibers have been used, given heightened awareness of the environment developers are now focusing on natural fibers such as hemp, sisal and flax. Recently, for example, it was announced that nanofibers had been extracted from carrots, which, when integrated in synthetic resin, are intended to produce especially rigid but lightweight components. Material concept and properties

The greatest challenge for developers when using natural products is to guarantee stable properties. Much progress has been made in recent years and it is now possible to use reinforcing fibers from flax, hemp, kenaf, abaca, coconut, jute, ramie and sisal in certain product categories. Natural fiber-reinforced polypropylene in particular is a cost-effective alternative to technical plastics such as ABS, POM, and PA, as it can be effectively injection molded and boasts comparable material properties. In addition to synthetic plastics, 100% crude oil-free biopolymers can also be used as matrix materials to produce biodegradable products.

55

Properties  rapid growth // available worldwide // aesthetic transparency // flameretarding properties

BIO-based Materials

Sustainability aspects  conventional reinforcement fibers replaced by renewable raw materials // approx. 1/3rd lighter than conventional fiber composites // degradable with crude oil-free matrix

Natural fiber composites (NFC) Components of flax

cellulose

minerals

fat, wax lignin

Use and processing

hemicellulose

protein pectin

water

Protective helmets are a much quoted example of products that make use of plant fiber reinforcement, in which the fiber material is integrated in a duroplastic matrix by means of a molding procedure. Fiber-reinforced molded parts are also frequently used in the door cladding and rear shelves of cars. In the design field they are commonly used for seating shells and transport containers. Typical processing methods for plant fiber-reinforced plastics are molding and injection molding. Products

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Green LinE  This brand offers natural fiber-reinforced plastics for the manufacture of suitcases and other containers using injection molding, extrusion and compression molding. In addition to ecological reasons, the use of natural fibers is meaningful primarily on account of the low weight of molded parts and sound mechanical properties given similar production costs.

Circular tubes made of natural fiber-reinforced plastic (Source: H. Hiendl GmbH)

Mounting profile made of natural fiber-reinforced plastic (Source: H. Hiendl GmbH)

Processing flax (Source: Hess Natur)

Natural fiber composite granulate (Source: H. Hiendl GmbH)

Protective helmet made of natural fiber reinforced plastic (Source: Schuberth)

Lignobond This biocomposite consists of 40% polypropylene and 60% natural fiber. It was optimized for the injection molding process, has correspondingly positive extrusion capabilities and excellent elasticity. Water absorption is minimal.

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56 BIO-based Materials

Cellucomp  By means of a new process Cellucomp  extracts nano-fibers from carrots and uses these as fiber reinforcement for synthetic resins. In this way it is possible to make components that are very flexible and lightweight.

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Dakota Burl The composite material Dakota Burl  is based on agricultural fiber materials and sunflower seed-shells. It competes with hard wood as a material for panels. It can be processed using conventional techniques and colored with wood glazes. It is naturally brownish in color and has a visually interesting texture for shop construction and interior design.

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Biofiber Wheat The yellowish color of this panel material comes from wheat straw. The surface is very finely structured and features a natural grain. The material can be processed using the usual techniques and is suitable for many applications in architecture and furniture making. No dangerous gases are emitted.

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Arbofill  The Arbofill  brand encompasses high quality composite materials made of plastics and natural fiber additives, for example polymers mixed with spruce and beech fibers for injection molding, which are used to make complex components for the household.

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NaBasCo  NaBasCo  is a bio-material made of natural fibers such as flax and hemp, which are integrated in a crude oil-based resin system of polyester or epoxide. Natural fibers are approx. 30% lighter than glass fibers. The composite material has similar acoustic properties as wood. With its unique surface structure it is a particularly interesting choice for sanitation installations.

®

Floor protection system made of natural fiber-reinforced structures (Source: Greengran)

NFC lightweight panels (Source: Jakob Winther)

NFC table decoration (Source: Tecnaro)

Manufacturing suitcases and containers using natural fibers (Source: Jakob Winther)

Some 150 years ago, the English chemist Frederick Walton discovered the floor covering linoleum. As it is non-hazardous to human health and made of natural components, linoleum has experienced a comeback in recent years.

57

Properties  very durable // anti-bacterial // non-slip // sensitive to moisture Sustainability aspects  based on natural raw materials // compostable

BIO-based Materials

Linoleum Material concept and properties

Linoleum is manufactured from linseed oil and natural resins, sawdust, lime powder and natural color pigments. Its name is derived from the Latin “linum” (flax) and “oleum” (oil). It was widely available as a floor covering until the 1920s but in the 1950s lost out to textile covering and newer materials such as PVC. Linoleum is a non-slip surface and is thus most often used for flooring and table covering. It is manufactured by heating the raw materials, then spreading these on a base material such as jute. Given its high resistance to oils and fat, and the fact that is also slightly anti-bacterial, Linoleum is very durable. It is easy to clean and can be composted when no longer needed. use

Linoleum has long been a favorite with architects and designers for flooring and tabletops on account of its interesting structure and the fact that it is easy to color. The property profile makes it especially suitable for rooms with high hygienic requirements (not wet rooms). Previously, linoleum was used also as wall covering. Special cleaning agents are available on the market for the care of linoleum surfaces.

Linoleum tabletop (Source: Franz Faust Linoleumprodukte)

Barktex® is an innovative material made from the bark of the wild Mutubu fig tree. The company Bark Cloth ® started bark cloth production in cooperation with Ugandan farmers as early as 1999. The material has since become popular particularly with fashion and interior designers. In 2006 UNESCO declared the handcrafted manufacturing process a World Cultural Heritage. What was once a developmental aid project now stands on its own two feet and guarantees the livelihood of hundreds of African families.

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Properties  beige to dark brown in color // individually adjustable qualities // waterproof // light transparency Sustainability aspects  based on renewable raw materials // small-scale farming in developing regions // biodegradable due to crude oil-free resin matrix

BIO-based Materials

Material concept and properties

®

Pure Bark Cloth  is sealed with textile additives and made wear-resistant for use in design applications. Given its fine to leathery texture it is a valued natural material. Depending on the tree color it ranges from beige to dark brown. When special additives are incorporated the texture can assume elastic, waterproof, tear-proof and flame-resistant qualities. In order to make individual surface textures suitable for industrial products, laminates of the 3D material are compressed with a core layer of impregnated phenol or aminoplast papers.

Bark cloth materials

Use and processing

Bark cloth laminates are now used in furniture, automobile and yacht construction. The German Aerospace Center (DLR) is currently testing them as composite panels with high bending elasticity and impact resistance. Luminaires made of Barktex  are also available on the market. Given its transparency the material is also used for light canopies, partitions, door cladding and in stage construction.

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Bark cloth laminates are processed with tools fitted with hard metal, which, when cutting, should be obliquely sheared to avoid damage to fibers. Dispersion adhesive and condensation resin are especially suitable for gluing.

Bark cloth processing in Uganda (Source: Bark Cloth ®)

Bark cloth texture (Source: Bark Cloth ®)

Bark cloth composite used in vehicle construction (Source: Bark Cloth ®)

59 BIO-based Materials

Bark cloth lampshade (Source: Bark Cloth ®)

Agricultural waste products and natural materials are increasingly used for sandwich-structure light construction panels. One example of a material currently under development is maize cob board, a wooden material with a central layer of maize cobs without seeds.

Properties  no previous industrial use for maize cobs // density: 250-300 kg/m³ // high durability in axial direction // similar qualities to particle board // good heat insulation Sustainability aspects  use of agri­ cultural by-products // 50 % lighter than particle board // good noise absorption

Maize Cob Board (MCB) Material concept and properties

Use and processing

With their foam-like core structure, maize cobs possess positive heat insulation properties and have so far had no industrial use. Moreover, they have a low density (180–200 kg/m³) and can withstand mechanical pressure, especially in an axial direction. Being a by-product, maize cobs are available inexpensively in large quantities. Similarly durable to particle board, maize cob boards are suitable for furniture, interior fittings and door construction. They are approx. 50% lighter than conventional wood fiber panels. The finished panels have a density of between 250–300 kg/m³.

The aim of current research is to qualify maize cob board as a biological light-construction panel for furniture and interior design. Processing methods are being tested and will need to be competitive with those commonly used for timber processing. The dissection of maize cobs is still problematic, as is the binding of the middle layer. In addition to the favorable heat insulation properties, it is also expected to have good noise absorbing properties.

Maize cob in cross-section (Source: Kompetenzzentrum Holz GmbH)

Manufacturing a maize cob board (Source: Kompetenzzentrum Holz GmbH)

60 Biodegradable materials

Water-soluble Polyvinyl Alcohol (PVOH)…064 — Alkali-soluble Plastics…065 — Polycaprolactone…066

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61 Biodegradable materials

62 Biodegradable materials

In the European Union a material is considered biodegradable if, in an industrial composting process, it has decomposed by at least 90% within 12 weeks. In addition to products based on natural raw materials, under certain conditions some crude oil-based materials also fulfill this criterion, making them valuable for applications in medicine and agriculture, as well as in the hygiene and packaging industries. Here, the option of breaking them down into non-hazardous substances such as carbon dioxide, biomass and water offers a unique selling point. Possible applications range from wound dressings that decompose within a certain period of time and temporarily effective adhesives, to residue-free objects for hygienic environments and water-soluble capsules for cleansing agents and medicines. Biodegradable materials have proved their worth for packaging. These days, compostable bags are available in almost all supermarkets. Plastics based on cellulose or starch are often used in product manufacture. Crude oil-based products such as polycaprolactone, polyvinyl alcohol, certain copolyesters, and polylactic acid are also suitable in this respect. Driven by the desire to think in terms of material cycles, materials have also been developed that dissolve in certain conditions. One example is plastics that decompose in alkaline solutions. The decomposition process can be controlled by changing the pH balance.

63 Biodegradable materials

Ecoflex ® is a biodegradable plastic based on aliphatic aromatic copolyesters. It has similar processing qualities to PE-LD and is thus suitable for foil packages (Source: BASF press photo).

Polyvinyl alcohol was first produced in 1924 and is commonly abbreviated as PVOH. A special characteristic is its water solubility, which makes the plastic particularly suitable for water-soluble foils and packaging.

64

Properties  thermoplastic // highly flexible // properties dependent on humidity // high tensile strength // solvent-resistant // adhesive qualities Sustainability aspects  made not from renewable but from fossil-based raw materials // biodegradable when dissolved in water

Biodegradable materials

Material concept and properties

PVOH is a plastic with thermoplastic properties and has a whitish yellow color. It boasts excellent adhesive properties and has great tensile strength and flexibility. However, the mechanical properties are dependent on humidity as the plastic absorbs water, which initially makes it soft and later completely dissolves it. The plastic is resistant to oils, fat and solvents. PVOH has no odor and does not give off any dangerous vapors. Use and processing

Water-soluble polyvinyl alcohol (PVOH)

The main field of application is packaging, where polyvinyl alcohol is predominantly used for water-soluble packaging (e.g., bath pearls). It is also contained in shampoos, ointments, glues, latex lacquers and hairsprays as an adhesive and thickening agent. It is also used to manufacture modeling clay and as a thickening agent in hygienic products. Its positive adhesive qualities also make it useful in the paper industry. As a binding agent PVOH improves the whiteness of paper, while in fiber-composite constructions it is used as a release agent. Polyvinyl alcohol can be processed into leather-like products with softeners such as glycerin. In textile production it mostly forms the protective layer for spun yarns and is also used as the binding agent in metal injection molding (see p. 183). Like other thermoplastics, polyvinyl alcohol can also be extruded, injection molded, and thermoformed by the usual processing methods, to make foils, bags, containers, canisters and dishes. Foil production by blowing or pouring is only of marginal importance. Products

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Gohsenol Under the brand name Gohsenol a polyvinyl alcohol was launched on the market in Japan, which, given its water solubility and chemical stability, is used in many technical fields, for example, the textile and paper industries. Moreover, Gohsenol is used to manufacture coatings and is used in cosmetic products and the pharmaceutical industry.

PVOH bath capsules

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Sokufol  Water-soluble PVOH foils and bags were developed especially for the packaging industry. They

Use of PVOH in water-based paints (Source: Kuraray Europe GmbH)

Water-soluble PVOH foils (Source: Kuraray Europe GmbH)

have positive barrier properties for gases, are nontoxic and solvent-proof. Once PVOH foils have been dissolved in water they are biodegradable. The solution is transformed into carbon dioxide and water by microorganisms in treatment plants. In the waste incineration process PVOH foils are converted residue-free into CO2 and water.

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Elvanol  The most important applications for the Elvanol  polyvinyl alcohol family by DuPont include adhesives for paper, wood, textiles, leather and water-absorbent substrates, textile coatings, water-soluble but gas-proof foils and binding agents for pigmented paper coatings.

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Diminishing resources are making it ever more necessary to think in terms of material cycles. Nowadays, used plastics can rarely be reused for their original purpose owing to contamination. However, in the future it will be necessary to completely recycle used raw materials at the end of the product life cycles, and conserve the energy used in the process. Alkali soluble plastics – whose solubility can be programmed in terms of both time and solution speed – now make holistic cycles possible. Material concept and properties

This special property is achieved in a polymer based on acrylate and polystyrene by integrating carboxyl groups. The plastic is durable under water, though it can be dissolved under the influence of watery alkaline solutions. Thus even in the case of mixed garbage, materials can be sorted for recycling. The extracted polymer chains are cleaned and, by lowering the pH value with a weak acid, precipitated again. The quality of recycled materials is comparable with the original material.

65 Biodegradable materials

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Polyviol  Given the strong adhesion of Polyviol  to inorganic pigments such as kaolin and calcium carbonate the polymer is mostly used as an optical whitener in the paper and cardboard industry.

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Mowiol  These PVOH products have a wide field of applications. They improve the whiteness in paper, are used as a binding agent in light-sensitive substances and in the production of creams and emulsions. They are found as fillers in emulsion paint.

Properties  thermoplastic processing qualities // programmable solution // usage properties are similar to polystyrene // recycling without loss of quality Sustainability aspects biodegradable plastic // raw materials are completely recyclable in the material cycle

Alkali-soluble plastics

Waste after an event (Source: Belland)

Use and processing

The possible uses of polymers are comparable with those of the mass-produced plastic polystyrene. Processing is thus possible in all the normal production facilities for extrusion, thermoforming and injection molding. The special solubility makes the material an obvious choice, in particular as packaging material (e.g., catering cutlery, foils, dishes, labels, hot-melt adhesive). Other fields of use range from medical adhesive tapes to the temporary application of surgical drapes and coatings. In the washing process the tape is removed completely and the drapes can be reused.

66 Biodegradable materials

Medical adhesive tape (Source: Belland)

Although polycaprolactones are based on crude oil, these plastics are biodegradable. Their decomposition is initiated by microorganisms, which destroy the material anaerobically. They decompose in the ground within the space of just a few days. Aerobic decomposition in sewage sludge takes slightly longer.

Alkali-soluble disposable cutlery (Source: Belland)

Properties  thermoplastic processing qualities // decomposition by microorganisms // properties resemble those of polyethylene // high elasticity // low melting point Sustainability aspects biodegradable

Material concept and properties

Since the crystalline structure of polycaprolactones resembles that of the mass-produced plastic polyethylene, it also possesses similar thermoplastic qualities. It is easy to process, can be blended with natural raw materials such as lignin and starch, and possesses elastic characteristics at room temperature. As the plastic melts at just over 60°C, an abrupt temperature rise during its application should be avoided. The plastic can be stretched extensively before ripping. It boasts tensile strength of around 26–42 N/mm2. Polycaprolactones emit no poisonous chemicals. They adhere well to other surfaces and can be mixed easily with other thermoplastics.

Polycaprolactone Products

Use

Given this special properties profile, polycaprolactones are mainly used in degradable packaging such as bottles and foil, as well as in medicine. They are able to support the controlled discharge of medication or fertilizers and are also used as dressings for wounds and hot melt adhesive.

™ ™

Capromer Under the name Capromer , BASF supplies several polycaprolactone substrates that serve as components in the production of polyurethanes and casting elastomers, and as binding agents for coating systems and adhesives.

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Capa  These polycaprolactone substrates are part crystalline and have a low melting point and a lesser degree of viscosity. They are compatible with a large number of other polymers and are not poisonous. Their base color is white. These, however, are not used in the medical field.

67 Biodegradable materials

Embedded in micro capsules made of polycaprolactones (PCL), the pesticide waits to be released (Source: BASF press photo).

68 Recycling materials

Recycling Plastics…072 — Recycling Elastomers…074 — Recycling Steel…075 — Recycling Copper…076 — Recycling Aluminum…077 — Recycling Glass…078 — Foam Glass…080 — Recycling Solid Surfaces…082— Recycling Textiles…083 — Bonded Leather Materials…085 — Wood Compound Materials…085 — Wood Concrete…087 — Paper Made of Organic Waste…088 — Recycling Paper…089

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69 Recycling materials

70 Recycling materials

At the latest since it became clear that other resources, in addition to crude oil, will grow scarce in the coming decades, the reutilization – or recycling – of materials has enjoyed an increasingly high standing. According to current expert opinion, crude oil production will have virtually halved by 2030. Procuring important metals such as gallium, neodymium, titanium and indium will also be problematic. These are of crucial importance for future technologies such as thin-film solar cells, energy-efficient flat screens and electromagnets for hybrid vehicles. Moves to reprocess in particular metals such as steel, aluminum and copper, to collect and melt down glass, and to reuse scrap paper have been successful in recent decades. Not only does this save resources, it also substantially reduces the energy required to drive material production. Thus every ton of scrap tin plate used in the production of steel, for example, saves 1.5 tons of iron ore and around 650 kilos of coal. An important prerequisite of recycling is generally the capacity to separate the individual components of disposed materials into types. A range of technologies has therefore been developed to this end. One example is the recycling process for drinks cartons comprising a composite of 80% paper, a PE-foil layer and a wafer-thin aluminum lining. The cartons are shredded, then the fragments placed in a bath of water. The chemical pulp swells and can be extracted. The foil rises to the surface and can just as easily be extracted as the far heavier aluminum for example, then used in the production of cement products and sheet materials.

71 Recycling materials

used Drinks cartons

3. Re-use of remaining compound 1. Shredding and separating

Cement

Rock

Hygienic paper, corrugated board

2. Re-use of the fibers

Recycling of drinks cartons (Source: ALBA DASS Betriebs GmbH)

72

The market for plastics based on renewable raw materials is still small. The bulk of polymer materials available for design and architecture are derived from crude oil. For this reason, from an environmental perspective, the use of plastics should still be viewed in a critical light. However, if one considers the entire lifecycle of a product – including production, transport and disposal – plastics fare better than the majority of traditional materials.

Sustainability aspects  recycling thermo­ plastics is possible yet quite rare // recycled duroplastics serve as reinforcement material // energy-efficient in comparison with production of new goods

Recycling materials

Recycling plastics

Material concept and properties

The qualities of polymers, which in many respects are second to none, can primarily be traced back to their ability to adapt almost perfectly to the respective profile of the product in question. The low weight of plastics makes energy-efficient use possible, and impacts positively on resourcesaving transport. By integrating the functional elements in a plastic component, the number of parts involved in the technical construction can be reduced and production costs cut.

Methods for the disposal of plastics from Handbuch für technisches Produktdesign Recycling

Recycling thermoplastics (Source: ALBA DASS Betriebs GmbH)

Reusing the materials from sorted plastic packaging

Shredding and separating

Product recycling

Multiple product use for identical or different purposes

Material recycling

Re-processing of recyclate as re­ generated products or re-granulates

Drying and re-melting

Chemical recycling through material conversion (pyrolysis, solvolysis etc.)

Processing

ps

1

san

6

abs

6

1

1

pa

5

6

6

1

PET

pe-ld

pe-hd

pp

PVC

pc

pmma

pa

abs

Miscibility of various plastics from Handbuch für technisches Produktdesign

Final disposal

Flower boxes, tubes, drinks crates

Films

san

The quality of recycling is always dependent on the rigorous sorting of thermoplastic waste products. If this is not possible, there is always the chance of creating polymeric blends or thick-walled plastic products. Polymer blends are mixtures consisting of various thermoplastics, whose properties can be determined very easily through their composition. During their production, however, it is important to take the miscibility of individual thermoplastics into account. Cutting-edge processing techniques facilitate the conversion of roughly sorted waste plastics into posts, benches and playground equipment. To this end, the remaining parts are heated up as small pieces in an extruder and subsequently transformed into a pasty mass. This is the source material for the production of compressionmolded construction components.

Bench made of Durat ® designed by Karim Rashid (Source: Durat ®)

ps

At the end of a product’s lifecycle, there are various possibilities for recycling polymer materials. The most simple is the re-use for a component with the same function (e.g., plastic pallets, drinks crates). Thermoplastics (e.g., PP, PA, PMMA and PET) in particular, provide recycling opportunities. Subjected to heat, they soften and can be made into granulates of a type that can be used in plastic processing. However, the use of old plastics in the production of high-performance plastics is not usual, given the loss of quality. Duroplastic resin systems and elastomer plastics offer limited recycling opportunities, which are restricted to chemical conversion into basic components and the use of shredded recycled objects as filler material.

Energy recycling

Incineration of waste, old and residual materials

Land filling

Composting of bio­ logically degradable materials Composting of bio­ logically degradable materials

1 Production of plastics

pc

6

2

2

6

1

pmma

4

1

1

6

1

1

PVC

6

2

3

6

5

1

1

pp

6

6

6

6

6

6

6

Processing of plastics

Use of plastics

1

pe-ld

6

6

6

6

6

6

6

6

1

pe-hd

6

6

6

6

6

6

6

6

6

1

PET

5

6

5

5

1

6

6

6

6

6

1 = good miscibility

1

6 = poor miscibility

Com mercial/institu­ tional consumption

Individual consumption

e.g. industry, lo­ gistics, agriculture

Domestic use

73

Use and processing

A number of recycling methods have emerged on the plastics market in recent years. These are used in a wide range of applications and for the most part reveal unchanged processing properties. Panels and felts made from waste plastics are also available. Some designers have made a name for themselves by designing furniture based on recycled polymers.

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Keridur  Keridur  , a composite panel based on recycled PVC, boasts excellent properties for lightweight construction. Keridur  sheets for mobile applications – for example, in truck production and shipbuilding – weigh around 40% less than competing products. Furthermore, both the honeycomb core structure and a layered coating evince a high degree of stability. As much as 85–95% of the PVC recycled is obtained from old window frames and packaging foils. It is used for facades and interior fittings, as well as for concrete formwork.

®

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Recycling materials

products

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Varia Ecoresin In recent years numerous artificial resin panels for interior fittings, partitions and doors have established themselves on the market, into which almost anything that seems aesthetically appealing can be poured. From an environmental perspective, the use of organic materials such as rose petals, banana fibers and bamboo cane should be rated just as positively as the percentage of material used to produce the artificial resin (around 40%). A configurator can be used to make individual settings. Designers can create individual products by combining various structures and compositions to see what different effects can be attained.

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Smile Plastics Since 1994 this English company has consistently specialized in the production of polymeric materials from waste plastic such as bottles, CDs, pipes, rubber boots and cell phone casing. The waste materials are shredded and compressed into panels under the application of heat. Their special look makes them ideally suited for use in furniture and interior design, for tabletops, as counter cladding, and as waterproof flooring in bathrooms and kitchens.

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Tectan  The material Tectan  is based on used drinks cartons and residue from the production of packaging. The basic materials are sorted then shredded into 5 mm particles and heat-treated. A special process produces a paper/plastic granulate that can be injection molded. Typical products made of Tectan  include containers, edge protection and tube plugs.

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Wash basin made of Durat ® with 30 % recycled material (Source: Durat ®)

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Panels made from old cell phone cases (Source: Smile Plastics™)

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Siotec  Siotec  is made of 30% recycled plastic and 70% sand. The components meld at a certain temperature, producing a construction material resistant to weather, acids and impact, and with good heat insulating properties. Its break resistance exceeds that of concrete. Furthermore, Siotec  is some 30% lighter. It is easy to process, can be welded and glued. Typical applications are waterproof and steam-proof bathroom walls, acid collectors, and wall panels in stalls. Siotec  can be recycled in a variety of ways.

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Edilfiber  This material was developed for thermal insulation and sound proofing purposes for the construction industry. It comprises up to 80% PET, sourced from municipal waste collection. Edilfiber  does not contain any poisonous additives or binding agents and as such is harmless to human organisms. Both its mechanical and acoustic properties remain intact over a substantial period of time. The material is 100% recyclable.

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Durat  Durat  is a solid material for surfaces used in interior design, with a standard thickness of around 12 mm. It is polyester-based and has a raw material recycling component of 30%. Durat  is extremely durable and resistant to moisture and chemicals. Also, light polishing can renew its soft, velvety finish.

Panels made from old rubber boots (Source: Smile Plastics™)

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As elastomers cannot be plasticized by means of heat application, recycling elastomer plastics is not so easy. Elastomer raw materials from tires, flooring, shoe soles and inner tubes were dumped as rubbish for many years but their recycling potential has now been recognized. Crushed to granulate or ground to produce a fine powder, they can be used as reinforcement in plastics and in a wide range of applications.

Properties  electric and thermal insulation properties // anti-slip properties // shockabsorbent // waterproof Sustainability aspects  re-use of elastomer waste materials // suitable for secondary recycling, depending on use

Recycling materials

Material concept and properties

Recycled elastomers have similar qualities to the original material. The particles produced in the grinding process boast a particularly large surface area, outstanding insulation qualities and anti-slip properties. They can be poured as rubber-like resins. Recycling granulate in flooring, mats or wall elements can comprise as much as 70% of the total weight. Finely ground powder blended with molding compounds can account for 10–20% of the weight, and be processed using conventional injection molding equipment.

Recycling elastomers

Use

Elastomeric recycling granulate can be used with outstanding success in running tracks, playground surfaces and protective mats, as well as for urban furniture and road construction. In loose form, it is used as interspersed granulate for artificial turf, which alleviates joint strain and reduces the risk of slipping. It is also used as reinforcement in shoe soles, writing implements, suitcase wheels and vehicle accessories.

DalLastic® floor covering

Insulation mat made of elastomers

Products

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SOCC Gran  Rubber granulate is interspersed in artificial turf in order to cushion impact and protect the body from strain. SOCC Gran  is a recycled product sourced from used tires. It is only half as expensive as granulate made from new rubber. In order to attain the playing quality of natural turf, around 40–90 tons of granulate are used on a football pitch. The material cushions impact and reduces the risk of injury.

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DalLastic  This brand name stands for an outdoor floor covering, made entirely of recycled rubber granulate. It is bound in bright polyurethane resin and is therefore waterproof and regarded as an alternative to conventional surfaces made of wood, ceramics or stone. DalLastic  is available in thicknesses of 30–90 mm. Typical applications are outdoor areas such as decks surrounding swimming pools or roof gardens, balconies and patios.

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InstaCoustic Cradle  Up to 90% of this material may comprise fibers and granulate sourced from recycled tires. It displays very good electrical and thermal insulating properties and is therefore used for example, as insulation in flooring.

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Isolgomma RTA  Isolgomma RTA  was developed for acoustic insulation purposes and may consist of up to 90% recycled elastomer granulate. This is blended with cork particles in a latex matrix. It lends itself well to improving acoustic qualities in the construction industry and is mostly installed in flooring or wall paneling.

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Cradle

Cradle Packers 2 mm or 5 m m

30 m m

Cradle Base Packer 30 m m or 10 m m InstaCoustic Cradle ®

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DalLastic ® outdoor floor covering

Although in recent years the replacement of iron and steel products by light materials such as aluminum, magnesium and fiberreinforced plastics can be noted, iron alloys are still the most important metallic materials for industrial products. Iron and steel form the basis for 90% of all metal applications, as their production is cost-effective and their material properties can be altered by heat treatment or by alloying them with other metals. Nowadays, around 40% of all steel production (and 45% of sheet steel production) is based on recycled steel. The manufacture of steel products from scrap iron as opposed to pig iron is more energy-efficient, given the new recycling processes now available. Material concept and properties

Steel can be melted down to produce construction components, without restrictions and without impairment to its quality, by using the electric arc process. In an inductive procedure using electrodes, scrap steel is melted at a temperature of around 3,550°C to create crude steel. This technology can be used to recycle even stainless steel residue and alloyed elements with high melting points. In order to avoid heat loss, the resulting slag is foamed in state-of-the-art plants, and isolates the hot steel from the furnace wall. This process enables energy consumption to be reduced by 85% and CO2 emissions by 70%. The slag is subsequently used in the cement industry. With a proportion of around 0.06–2.06%, steel contains substantially less carbon than iron, making it considerably more malleable. It is therefore not rigid and brittle like iron-based materials and can consequently be processed into different shapes. By blending steel with other metals such as aluminum, cobalt and vanadium, its properties can be adapted to the required application. This is possible also when recycled types of steel are used. Chrome improves the material’s abrasion properties while wolframite makes steel more heat-resistant. Blending it with silicon increases the metal’s machining properties while manganese increases its rigidity and durability

75

Sustainability aspects  general recycling // improved energy balance achieved through new processing technique // reduction in CO² emissions by around 85 % // reduction in environmental destruction through lower ore requirement

Recycling materials

Recycling steel corrode is of particular interest. In recent years a whole range of sculptures and installations have emerged, which uses the material’s reddish brown rust as an aesthetic hallmark. The ensuing patina develops its true colorfulness only with the passage of time.

Unsorted metal waste (Source: Becker GmbH Metall- und Schrotthandel)

How the electric arc process works from Handbuch für technisches Produktdesign

Filter

Steel strips on the roller (Source: ferrex)

Scrap and sponge iron

use

Nowadays, recycled steel is found in virtually all areas of production. In most cases scrap metal from cars does not end up in production, but is instead used in the construction industry as reinforced steel, profile rolling steel, and rough sheets for use in the steel industry. In Switzerland, for example, the proportion of recycled steel used in the construction industry is almost 100%. In the packaging industry around 60% of steel used comes from recycled material. For sculptors and architects, the tendency of unalloyed steel to

Carbon electrons

Removable lid Furnace vessel

Steel

Slag

Stake made of rusted steel Steel pan

Slag pot

Given copper’s high degree of resistance to corrosion, specific mechanic properties and excellent thermal and electronic conductivity, copper and its alloys (bronze and brass) have long ranked among the most important metallic materials for architecture, sanitation facilities, boiler construction, plumbing systems and electrical cables. Since it can be completely recovered after use, without any loss in quality, copper has a particularly high recycling quota. The European Copper Institute estimates that around 80% of the copper mined by human hand since Antiquity is still in use. Recycled products cover 40% of global demand for copper. In Germany the proportion recycled is as high as 50%.

76

Sustainability aspects  recyclable without any loss of quality // energy-efficient recycling

Recycling materials

Recycling copper

Material concept and properties

Copper for recycling can be recovered from scrap metal, electrical cables, wire and pipes, with minimal energy consumption. It has the same physical and chemical properties as the primary raw material. As copper smelting and refining plants need to ensure a purity level of 99.9% for recycled copper, electronic waste (e-waste) is shredded and its respective parts – plastics, ironbased metals and copper components – are sorted by type. Residue from copper production is then reused in closed material cycles. Owing to copper’s high material value, dumping copper waste in depots is now largely ruled out. Pure copper’s property profile can be adapted for particular applications by blending it with alloys. In particular, alloys from copper and zinc – such as brass – or

€ 10 cent coin made of “Nordic Gold”

Copper residue (Source: NordSchrott International GmbH)

those from copper and tin are very important in many application areas. Copper-tin alloys with a copper content of at least 60% are categorized as “bronzes”. A distinction is made between phosphorous, tin and aluminum bronzes, according to the type and proportion of alloy content. The addition of nickel produces a silver-white or stainless steel-like surface. Copper alloys with zinc and nickel are known as new silver. Use and processing

As sheet copper is easy to process, highly weatherresistant and boasts interesting visual qualities, the use of copper materials for roofs and facades has proved very popular in recent years. Components for the ship-building industry, decorative wall plates for interior design, as well as door and window elements are further applications for recycled copper that are of interest to designers and architects. Its anti-bacterial properties make it particularly attractive for handles and coins. The € 10, 20, and 50 cent coins, for example, consist of so called “Nordic Gold”, an alloy made from 89% copper, 5% aluminum, 5% zinc and 1% tin. Copper-based shape memory alloys (SMAs) are also regularly cast or melted. Lately, they have been used in product and fashion design. As a rule, recycled copper and copper alloys are mold cast or remolded by applying heat. They can be welded or soldered and are ideally suited for the treatment of surfaces. Copper materials can be permanently colored by chemical means. The green patina that ensues over time from weathering, often desired for aesthetic reasons, can be artificially created with three parts copper carbonate, one part aluminum chloride (salmiak), one part copper acetate, one part tartar, and eight parts acetic acid (acetic essence).

Facade made of sheet copper (Source: Bauklempnerei Peter Ness)

Sourcing aluminum from bauxite consumes an enormous amount of energy. In comparison, producing copper requires only around 1% of this amount. However, because of its low weight and the ease with which it can be processed, aluminum alloys are in widespread use in industrial products. In most industrial nations therefore, a third of the aluminum produced is now being extracted from recycled secondary aluminum, as reconditioning scrap aluminum requires only around 10% of the energy required when it is first extracted.

77

Sustainability aspects  fully recyclable without loss of original properties // energy-efficient compared with manufacture of new product

Recycling materials

Recycling aluminum

Material Concept and Properties

Aluminum can be recycled in its entirety without losing its original properties. First of all, however, it must be purified and freed of foreign bodies. Aluminum surfaces can be recognized by their silver-white color. A thin layer of oxide protects the metal from corrosion. At 2.7 g/cm3, aluminum exhibits a low level of density compared with other metals. Given the low level of gas permeability, aluminum is often used for packaging foodstuffs. Its electrical properties are good. To improve its mechanical properties it is generally alloyed with copper, manganese, magnesium, or zinc.

Used aluminum packaging

1. Shredding and separating

Aluminum cans, films, bowls

Use and processing

Recycled aluminum products are used in all those areas where scrap aluminum is also recovered. The proportion of recycled aluminum totals in excess of 50% in the traffic sector, followed by the construction and packaging industries. Aluminum alloys are easy to reshape and can be processed by casting. Foaming is also possible (see Metal Foam, p. 104).

4. Rolling

Products

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Alulife  This panel material is produced from virtually 100% recycled aluminum and, given the high quality of its finish, is suitable for flooring, doors, tables, shelves and other furniture. It is suitable for both indoor and outdoor use. The panel material is available in thicknesses of 3–5 mm and various colors for use as wall cladding.

2. Removal of foreign materials

3. Melting and casting Recycling aluminum (Source: ALBA DASS Betriebs GmbH)

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Alkemi This composite product consists of around 40% aluminum shavings, which are firmly embedded in a resin matrix. The panel material is available in a number of colors and, given its sealed and resistant finishes, is suitable for kitchens and furniture. Combined with stone, glass and plastic laminates, it offers enormous aesthetic potential for interior design.

78 Recycling materials

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Alusion As a rule, recycled aluminum is used in the production of aluminum foams (see Metal Foam, p. 104). Alusion is a panel material with an open or closed cell structure, which has only 10% of the volume of the full material. Aluminum foam with large pores is translucent and can be used in lamps to create attractive spatial effects. It is also used for furniture, interior fittings and trade fair stands.

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Doluflex  This composite “sandwich” panel with highly stable properties suited to lightweight construction is made from up to 50% recycled aluminum. Its core comprises a trapezoidal aluminum structure, to which two covering layers are applied. In combination with stainless steel or covering layers of galvanized sheet metal it offers a broad range of solutions for interior fittings. The panel is available in lengths of up to 3.5 m.

Alkemi™ panel material (Source: Alkemi™)

Alusion™ panel material (Source: Alusion™)

Glass is an amorphous solid with a structure similar to that of liquids. This is thanks to its translucent properties. Glass’ other properties stem from its chemical composition and the additives blended with it. These can be varied depending on the intended use.

Sustainability aspects  conservation of natural resources // energy-efficient production // recyclable

Material concept and properties

Recycling glass

Nowadays, a not insubstantial proportion of the materials used in the production of glass stems from recycled glass. As a result of its rigidity and inertia, glass can be crushed after purification then returned directly to the production process. The loose atomic structure of glass makes it easier to blend with foreign materials. However, the use to which recycled glass can be put depends in each case on the type of glass. Standard everyday glass can be returned to the process an infinite number of times without any loss of quality. Glass made entirely of recycled glass is based on normal household glass.

79

use and processing

There are numerous examples of products made of recycled glass that go beyond everyday objects. Scrap glass is used in the production of partitions, lampshades, tiles and 3D glass materials. Panels made of recycled glass are just as available on the market as mosaic tiles, with a recycled proportion of between 65–80%, as well as wall coverings and flooring made from waste glass. Glass made of recycled material can be processed using all techniques known to the glass-making industry.

Recycling materials

Waste glass

Products Glass bottles, Glasses

1. Separate collection by color in containers

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Bio-Glass  This panel material is made of 100% recycled glass. Since it contains neither additives nor coloring agents, it can be recycled in its entirety. Only a small amount of energy is required for its production. Given its special aesthetic appeal and sealed finishes, Bio Glass  is used for worktops, furniture coating, and in interior design.

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4. Shaping

2. Sorting, crushing, cutting

Recycled glass in use in the kitchen (Source: Coverings Etc)

3. Melting Recycling glass (Source: ALBA DASS Betriebs GmbH)

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Stax Stax glass panels are produced from waste glass by melting stacked pieces of glass. The result is a material finish with a 3D look and reflecting surfaces and edges. One square meter of the glass weighs around 14.5 kg and varies in thickness between 1–1.5 mm. A reflective surface stuck on its rear side emphasizes the material’s particular visual qualities and also increases its stability.

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Blazestone Blazestone is produced without the addition of oxides or coloring agents and contains up to 50% waste glass from bottles and windows. It is used for ceramic tiles, crockery and decorative articles.

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Malachite structure made of recycled glass (Source: Coverings Etc)

Trend Glasmosaike Mosaic tiles are produced by Trend in the tra-

ditional square format measuring 20 x 20 mm and 15 x 15 mm, using up to 80% recycled glass. They are used in flooring, as wall coverings and in sculptures. The mosaics have a waterproof and as such frost-resistant surface, making them suitable for outdoor use. A configurator is available for designers, artists and architects who wish to create an individual design.

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Icestone Icestone comprises glass particles from waste products, which are incorporated in a cement matrix. It is available in 24 different colors, but by varying its composition can be adapted to meet clients’ specific needs. This stone material is used in bathrooms and kitchens and to create special atmospheres in public and commercial buildings.

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Rockglass© Rockglass© has an aesthetic resembling that of stone and is made up to 30% of recycled glass. This tile material is available in various sizes and colors, and is used in decorative coatings and for wash basins and flooring in residential and commercial buildings.

Recycling materials

Hailstone© This material is made almost entirely of recycled glass from medical waste such as small bottles and ampoules. It is used in interior design as a coating material but can also be used for outdoor walls. The panel is sold in lengths of between 7.5–35 mm. Glassshells Recycled glass is used in the production of this laminate of glass and natural mussel shells. The material is surprising for its particular transparency and is especially suitable for backlit applications. TTURA© This panel is composed mainly of glass shards and residue. The pieces and particles of glass are blended with resin without added solvents, and are suitable for use both indoors and outdoors. Relight© The company Relight has specialized in the disposal and processing of old electrical appliances. Chalk-soda glass is extracted from the remains of fluorescent lamps and used to coat stoneware and porcelain.

Panel material made of recycled glass and mussel (Source: Glassshells)

Ceramic tiles made of recycled glass (Source: Blazestone™)

Properties  high strength and durability // stable // non-inflammable // vapor-tight // medium heat conductivity Sustainability aspects  positive energy and emissions balance // above-average lifecycle // recyclable

On account of their high strength and durability, foam structures made of glass have been in use for around fifty years, particularly for heat insulation in areas exposed to compressive stress. Nowadays, recycled glass is predominantly used in their production. Foam glass contains no harmful materials, is innocuous to human health and has a positive energy balance. Material concept and properties

Foam glass

The source materials are ground to a fine glass powder in mills and, with the addition of carbon dioxide at temperatures of between 900–1,000°C, distended to form closed-cell foam structures or, if mixed with water, foam and binding agents, to form fine-pore glass granulate. Glass foam is vapor-tight, non-inflammable (Class A1 construction material), acid-resistant, and does not absorb moisture or swell. It has a similarly low expansion coefficient to steel and concrete, and a mid-range level of thermal conductivity (0.040–0.555 W/mK.)

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Use and processing

Foam glass is used for heat insulation purposes, particularly where a high level of stability as well as waterproof and vapor-proof properties are called for. It is used for example, in the construction of parking decks, roofs with greenery, patios and foundations. Furthermore, foam glass granulate is used as a lightweight construction additive in masonry materials, composite wall systems, floor ballast, light and refurbishment plaster, and filler. Panels made of foam glass are normally laid with cold-bonding adhesive or bitumen. Standard machining techniques are available for processing it. On account of the high vapor concentration, there is mostly no need for a vapor barrier in a layered structure.

Recycling materials

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Resopal  -A2coustic This is a sound-absorbing compound panel with a middle layer made of a foam glass core. It is flanked by perforated panels so that the sound waves are lost in the fine pore structure of the distended recycled glass granulate.

Products

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Foamglas  Foamglas  are panel materials made from glass foam with no added CFC or binding agents, which boast high insulating properties. They come with a minimum thickness of 30 mm and measure 600 x 600 mm, 600 x 450 mm, and 450 x 300 mm. Foamglas® boards for perimeter and floor insulation have a coating of paper, plastic or metal foils. The compressive strength of the various products available is between 0.4–1.7 Nmm2; its thermal conductivity is between 0.038–0.050 W/mK.

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Foamglas ® panel material (Source: Foamglas ®)

Foam glass floats in water (Source: Liaver ®).

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Poraver  foam glass granulate Poraver® is a distended, cream-white round granulate made from recycled glass. It is suitable as a filling agent for heat and sound insulation of dry mortar, masonry materials, panel systems, and adhesives. Its thermal conductivity is around 0.070 W/mK. As foam glass granulate is alkaliresistant, it is particularly suitable for processing with chalk and cement. Exact particle sizes of between 0.04–1.0 mm and its extremely low weight optimize the formula structure as well as the material and processing properties required for various products.

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Liaver  foam glass insulation This composite material consists of an insulating layer made of ceramic clay with permeable air pores and a cemented layer of foam glass. In the concrete factory the various layers are applied in a wet state. Given the natural source materials, the result is a construction material with outstanding biological, insulating, and heat-retaining properties. Since slight oscillations in temperature are leveled out, a pleasant room environment is created all year round. The compound exhibits efficient noise insulation and offers the highest possible protection against fire. The heat transfer coefficient is below 0.30W/(mK).

Poraver ® round granulate made of recycled glass (Source: Poraver ®)

Sound-absorbing composite panel with foam glass core (Source: Resopal®)

Processing foam glass with cement (Source: Poraver ®)

Properties of Liaver ®

Grain size

mm

0.1 to 0.3

0.25 to 0.5

0.5 to 1

1 to 2

2 to 4

Loose bulk density

kg/m³ (± 15 %)

450

300

250

220

190

Grain density

kg/m³ (± 15 %)

800

540

450

350

310

Crushing resistance following EN 13055-1

N/m m² (≤ 15 %)

3.5

2.9

2.6

2.4

2.2

Thermal conductivity λ R

W/(mK)

not defined

0.07

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Concrete pipes, concrete-fiber construction panels, cavity blocks and paving stone: natural stones are no longer or only rarely used nowadays in the construction industry, having been superseded by industrially manufactured stone products. These are composed of natural materials, and are compressed and hardened under the influence of a mineral binding agent. This production process creates ideal conditions for the use of treated waste materials. This way, waste from the mineral-refining industry and the construction sector can be reused in much the same way as residual plastics and glass.

Recycling materials

Recycling solid surfaces

Material concept and properties

Filler serves to improve the mechanical and weather-resistant properties of stone materials. Furthermore, heat-retaining and insulation properties can also be improved through the incorporation of air-retaining materials. Adding fibers leads to the enhancement, in comparison with standard types, of the material’s tensile strength and the compressive strength of what is known as fiber concrete. Adding fibers also helps prevent cracks spreading. Incorporating synthetic fibers in the concrete produces what is referred to as textile-reinforced concrete. In addition to the advantages already mentioned, it is particularly low in weight. use

Stone materials based on recycled mineral source materials and added plastic or foam glass are used in a wide range of construction solutions. The improved heat insulation properties are particularly suitable for use in foundations and flooring.

Sustainability aspects  re-use of waste materials // lightweight properties and heat insulation qualities

Properties of various fiber materials E-Module [N/m m²]

Tensile strength [N/m m²]

Material

Density [g/cm³]

Concrete C25/30

2.40

30,000

Steel fiber

7.88

210,000

1,000

PP fiber

0.90

4,200

560

Glass fiber

2.40

73,000

3,400

2.6

Products

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Rastra  Recycled polystyrene is blended with this concrete material to improve heat and sound insulation. For this reason it is lighter than normal concrete but is sufficiently rigid for load-bearing walls and supporting structures. Rastra  is used in floors and ceilings for heat and sound insulation purposes.

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Porocom  On account of the spherical base material it is very flexible in the ways it can be made into a wide range of the shapes used in the construction industry. The granulate comprises recycled foam clay or foam glass with a porous cell structure. It is bound by a powder coating, which liquefies at 200°C. The proportion of air in the cells is around 30%.

®

Fireclay  BottleStone BottleStone ceramic surface material is made of 80% glass from recycled bottles. It provides a sustainable alternative to stone panels and boasts similar aesthetics. Furthermore, it is scratch-proof and dirt-repellent. BottleStone ceramics are available in Mocha, Cobalt, Espresso and Sand with a smooth, lightly polished or ground finish. Building made of the concrete material Rastra ® (Source: Rastra ®)

83 Recycling materials

Spherical construction material Porocom ® (Quelle: Porocom ®)

At the latest since textile fibers found their way into technical applications with lightweight properties, the variety and number of synthetic fibrous materials on the market has been increasing continually. The best examples are membrane textiles and polymer cushions for roof and hall constructions, industrial filters, and spacing textiles for the construction industry and aviation. Material concept and properties

Synthetic fibers have the advantage that their properties can be adapted to meet the exact needs of each intended use and be produced at a constant quality level. The majority of synthetic fibers are derived from thermoplastics such as PTFE, PET or PVC. After being properly sorted, these materials in particular can be melted and re-shaped, and are ideal for the manufacture of new products. They are used in textile and fiber production in granulated form.

Sustainability aspects  recycling of thermo­ plastics is possible and very simple // energy-efficient compared with manufacture of new product

Recycling textiles

use

In fashion design in particular, a whole host of designs have emerged recently featuring recycled plastic waste. Given that they are easy to produce, felts and fleeces are particularly suited for integration with recycled fibers. They are also increasingly being used in the production of synthetic leathers, and for insulation materials in the construction industry and geo-textiles for landscaping. BuzziLight lamp made of felt based on waste packaging (Source: Buzzispace ©)

Products

Buzzispace© Waste packaging is increasingly being used in the production of textile polymer fibers. What is new about the latter’s use in product design is not the material’s property per se but rather, the fact that a product, even a classic material such as felt, can attain a totally new standing by communicating the topic of sustainability – as the work of designers at the Belgian company Buzzispace clearly illustrates.

84 Recycling materials

®

Batyline  The textile fabric made by the French company Ferrari is created entirely from scrap material and is suitable as a cover fabric for both outdoor and office furniture. Having established a Europe-wide collection network and a complex recycling process, the producer is now able to recycle coated textiles in a closed cycle. Individual colors and weaves can be produced as of approx. 1,000 m2. BuzziScreen room divider made of recycled packaging waste (Source: Buzzispace ©)

Nobody Chair The chair by Danish design duo Komplot consists of industrial felt that is sourced for the most part from recycled PET bottles. This piece of furniture is the first chair with a self-supporting pure material structure. Its geometry is shaped by thermal pressing in a tool molding. Waterfront Waterfront is a furniture cover produced from up to 100% recycled polyester. A PTFE covering reduces the risk of soiling.

®

Fibertex Pan  This felt, made from up to 50% recycled fibrous material and polyester fibers, boasts high heat and sound insulating properties and is often used in the construction industry for roof and impact insulation, without the addition of toxic matter. After it has been dismantled the material is fully recyclable under the influence of heat. It can also be shaped three-dimensionally. Patagonia© As long ago as 2005 the American outdoor clothing manufacturer Patagonia© stated that it was aiming to produce a third of its new textiles from recycled materials. To this end, it established a collection system so that customers could return worn-out garments for recycling. As a result, the company expects to need less crude oil-based polyester material.

Nobody chair made of PET felt by Danish design duo Komplot

BuzziSkin 3D tiles made of recycled packaging waste (Source: Buzzispace ©)

Lounger featuring a cover fabric made of recycled plastics (Source: Batyline ®)

85

Bonded leather is a fiber composite that is used as an alternative to natural leather. It comprises waste products from the leather industry and natural latex.

Recycling materials

Material concept and properties

Other components include vegetable tanning agents and fats, such that the composite consists up to 95% of natural source materials. In a process similar to that for making paper, these are initially shredded then the non-woven fleece mixture is drained under vacuum in a looped screen, dried, and cut into rectangular shapes. The process has now been optimized such that even thin materials under 1 mm thick, homogenous properties, and sewn finishes can be produced. Use and processing

The shoe-making industry is the largest consumer of bonded leather. The cheap substitute is used for example, in the production of soles and heels. Furthermore, fiber materials are applied in the fashion industry and for interior design, in the production

Sustainability aspects  95 % natural source material // exploitation of waste in the leather industry // simple to process // recyclable

Bonded leather materials of bags and belts, and desk pads. Substitute leather material is easy to process. Depending on the thickness it can be cut with a pair of scissors or a sharp cutter and then riveted, glued or even sewn. For interior fittings it is available on the market in various panel formats. In furniture production it is applied to wooden surfaces with PVA glue. For upholstery purposes it is available from retailers in rolls in thicknesses between 0.6–1.8 mm.

of 0.6–1.8 mm. The basic colors are natural gray, brown and anthracite.

®

Lederett  Lederett  fiber material consists of non-woven, irregularly layered fibers within a frame-substance comprising various leather fibers. When blended with natural binding agents it becomes a sturdy replacement leather material. It is available in panel and roll form.

®

Products

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Ledano  Ledano  is a surface material produced from leather fibers and designed specially for furniture design and interior fittings. It is abrasion-proof, UV-resistant and composed almost entirely of sustainable raw materials. Ledano  is largely used as a full-cover surface material for cupboards, tables, doors and wall cladding. In a 3D process it can also be processed for shaped wood chairs. It is available in twelve silk-matt colors and thicknesses

®

®

Wall cladding made of substitute leather material (Source: Ledano ®)

To protect forests and ensure a supply of materials with constant properties, a wide range of wood panel materials were developed in the 1990s. These are made of various different layers, or are based on waste material from the timber trade (shavings, sawdust). As a result of the cross-wise adhesion of shavings or the erratic structure of wood fibers, undesired size fluctuations caused by changes in the moisture content of the surrounding air (hygroscopy) can be avoided. The panels’ properties can be adapted to the purpose at hand by varying the type of wood, the amount of binding agent, the pressing pressure level and the position of the shavings.

Salamander Bonded Leather The shoe manufacturer Salamander is the largest producer of bonded leather. A fiber material between 0.3–0.35 mm thick is produced for book binding under the brand name Cabra  .

®

Tretford veledo Tretford distributes the veledo prefabricated flooring system, which is based on Salamander’s bonded leather. This is laid on a HDF base plate and laminated with cork.

Properties  constant qualities // stable dimensions // minimal swelling // interesting surface textures // low cost Sustainability aspects  made from waste materials // recyclable, when biodegradable resin systems used

Wood compound materials

86 Recycling materials

Waferboard Waferboard is the term used for wooden materials in which particularly short splints with lengths of a maximum of 30 mm are glued and compressed in no particular direction. Waferboard is more cost-effective than other materials and is used as an upholstery material, and for roof constructions and partitions.

Material concepts and use Kraftplex ® panel material (Source: Material.FranzBetz)

OSB

Cement-bound chipboard Duripanel® (Source: Eternit)

Laminated veneer lumber (LVL) veneer chipboard LVL is a wooden material comprising several 3 mm thick veneer plies, the course of whose fibers is almost completely identical. For special applications, the crossways configuration of a few veneer plies balances out weak points caused in production or by moisture. The timber for laminated veneer lumber is sourced from swift-growing coniferous trees such as spruce and pine. The individual layers are bonded with resin to produce a high-strength water-resistant material. For this reason LVL is used as outdoor panels and beams for facades, bridges, and roofs. It is normally inflammable and assigned to fire prevention class B2. Oriented strand board (OSB) coarse particle boards Given their visually interesting coarse finish and low price, OSB boards are popular with designers and interior designers. They are produced from 60–150 mm x 0.5–1 mm wood chips that are laid crosswise to one another in several layers and then glued together. OSB boards boast a similar bending strength to MDF and are more tensile than normal flat boards. Coarse particle boards have gross densities of between 550–700 kg/m3, are between 8–22 mm thick and display a mere 0.035% swelling. They are primarily used for flooring and walls. Laminated strand Lumber (LSL) LSB is a special OSB timber material with a high degree of stability. Particularly long splints (of up to 30 mm) are used in its production. As such it is categorized as long chipboard. Its gross density is just over 600 kg/m3. Laminated strand lumber is used in timber construction at a maximum size of 2,440 x 10,700 mm and in thicknesses of 32–89 mm.

Balsaboard

Parallel Strand Lumber (PSL) PSL is a particular extrusion board composed of various veneer strips. These are mixed together to form a mass, bonded with artificial resin and compressed in a heated press channel. The extrusion process enables the production of particularly long timber material, such that parallel strand lumber of up to 20 m in length is available. The heavy-duty beam material is used in framework constructions as well as for posts and supports, both indoors and outdoors.

Products

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Parallam  This strip veneer material, which is produced by an American manufacturer, consists of 16 x 3 mm pine-sourced, peeled veneer strips, glued parallel to the base timber’s longitudinal axis. It is typically used as a construction material with a high degree of stability. Typical uses are supports and beams. Its density is 600–700 kg/m3; its lengthwise shrinkage is a mere 0.01%.

®

Duripanel  Cement-bound chipboards consist of conifer chips, cement and mineral additives. They have a cement-gray, smooth surface and are resistant to weathering, frost and insects. As such they are ideal for rear-ventilation facades, wall cladding and as particle board flooring for indoors and outdoors. Depending on their thickness they can also be used as sound and heat insulation, or as load-bearing cladding. Duripanel is assigned to fire prevention classes B1 and A2.

®

Balsaboard This composite wooden panel is not only lightweight and filigree, but also boasts particularly good rigidity on account of its special sandwich structure. This makes it ideally suited to use both indoors and outdoors, wherever weight plays just as large a role as load-bearing capacity and stability. Its core consists of balsa wood, which is protected from external influences by thin MDF or cross-ply veneer. Balsa is the lightest of all fast-growing tree types. A producer in Ecuador has specialized in using it in the construction of surfboards. Resin with a base of lentil seeds is used as a matrix material, to ensure its biodegradability.

™

Agriboard Agriboard specializes in manufacturing wooden materials based on laminated strand lumber and compressed wheat straw. Since natural binding agents are used, the construction material can be entirely composted. It is used as a construction material and for insulation purposes. Entire building constructions are available, both for commercial and private use.

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Recoflex This material comprises up to 95% renewable resources and is marketed as elastic chipboard. It is based on wooden and cork particles, latex

®

87

Ecopan  Honeycomb structures are used at the core for wooden panels with particular lightweight qualities (see Chapter 04). Ecopan  is a product comprising a honeycomb structure sandwiched between sheets that are 10–120 mm thick. The panels are suitable for use as a lightweight construction material, particularly in vehicle manufacturing and the construction industry. Ecopan  is easy to process and transport and therefore very popular for shop interiors and furniture construction. It can be protected from water and other liquids with special coatings.

®

Recycling materials

Lamp made of kraftplex ® (Source: Material.FranzBetz)

and polyurethane, and is produced in molding presses. Recoflex is used primarily in the production of curved molded parts, as it is flexible in all directions. As no formaldehyde is used in its production, it is 100% recyclable. It is available in sheets up to a maximum size of 2.3 x 1.25 m. Recoflex coated on both sides with wooden veneer is also available.

Considered from an environmental perspective, wood outperforms all common con­ struction materials. Unfortunately, the latter’s potential has not been sufficiently exploited to date. Yet now, given current debate on the environment, research and the development of new materials for the construction industry are again being seen as a priority. Wood concrete in particular displays exceptional potential in terms of its weight to stability ratio, sound and heat insulating properties, and aesthetic appeal. Material concept and properties

Wood concrete is a classic particle composite material. It consists of wood chips (largely low grade conifer wood) and quick-hardening cement. Depending on the level of stability required, the volume ratio for plastic consistency is set between 1.4 and 2.6. For an earth-moist consistency compaction is realized by tamping. This assures timber to cement volume ratios of between 3.1–3.4. Adding calcium chloride accelerates the setting process. Molds are made for processing, in which the plastic timber-concrete mix is compressed. After drying, lacquers or paint serve to protect the material from weathering.

®

kraftplex  kraftplex  is made of 100% wood fibers and, given its metal-like stability and plasticity, offers an alternative to sheet metals. Neither chemical additives nor bleaching and binding agents are used in its production, making it entirely biodegradable. The wooden sheet can be processed by 3D deep drawing, and cut by laser beam or water jet. Its main areas of use are interior design and furniture construction.

®

Agriboard™

®

Properties  low density (gross density: 450-900 kg/m³) // good mechanical qualities (compressive strength: 7 N/mm²) // high level of heat insulation (thermal conductivity level of 0.1 W/mK is possible) // low energy consumption in production // zeroemission product Sustainability aspects  zero-emission products, low energy consumption // mineral components replaced by lumber industry waste // positive influence on spatial lighting effects // improved heat insulation

Wood concrete Use and processing

Wood concrete has previously been used almost exclusively in the construction of breeding and nesting areas for endangered animal species, identical to those found in natural conditions. Yet now, the construction industry has also found a use for wood concrete compound construction panels. They provide excellent heat insulation and good general thermal properties. Indoors, earth-moist consistencies are used for suspended ceilings, while plastic consistencies are used for exterior facade construction and are expected to replace purely mineral construction materials in the long term.

Bird table made of wood concrete (Photo: Olaf Mertens)

88

Products

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Isospan  Isospan  products are made of wood chips, cement and minerals. They were developed in particular for the construction industry and offer good insulation properties and low-level thermal conductivity. Prefabricated wall systems make it possible to create structures with no thermal bridge. The company’s guiding principle in developing this new form of construction product was to minimize environmental damage, particularly the pollution of air and water. The products are recyclable and the company also takes back cleanly sorted wood concrete waste for further processing.

®

Nowadays, almost 95% of industrial paper production is based on wood. This was not always the case, however, as wood fibers are significantly shorter than those from plants and textile waste products, which today still form the basis of washi paper. Some 2,000 years ago in Ancient China, raw material from rags (textile waste) was converted from bast to cellulose. This marked the transition to paper, as we know it today. The fabrics were allowed to rot and then crushed under water until a thick pulp emerged, which then, using a sieve, could be spread into even, two-dimensional surfaces and left to dry. As such, using alternative organic waste for paper production and easing the burden on tree resources would seem to be an obvious approach.

“Cartamela” apple paper

Elk droppings for paper production (Source: Academic dictionaries and encyclopedias)

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Isolith  Isolith  is a dual-thickness wall offering both formwork and insulation properties. Its concrete core serves as a load-bearing element and the outer timber layer as insulation. The 15 cm-thick light concrete core stores heat and slowly releases it inwards. The inner timber layer supports swift installation. The heat transfer coefficient is around 0.56 W/m2K.

®

Recycling materials

Dry gross Thermal density conduc- tivity (kg/m³) (W/mK) Isospan ®

500

Polystyrene

15

0.10 0.040

Concrete 2,200 2.10

Sustainability aspects  use of waste materials

Paper made of organic waste Material concepts and use

Paper made from the waste from apple juice production Alberto Volcan is the inventor of paper he makes from the waste from apple juice. He came up with the idea due to the very high cellulose content in apple residue. The paper is called “Cartamela” and, given the fact that it has good printing qualities compared with normal paper, is predominantly used as packaging material for the cosmetic industry as well as for organic foodstuffs and wellness products.

Paper made from animal excrement It is unusual to make paper from the excrement of animals, but an elk farm near the Swedish town of Östersund uses the droppings of its animals to produce hand-made paper. Elk droppings also contain a high proportion of cellulose and are used to make a light brown type of paper, which smells like bark and has a rough finish. It is predominantly used for high-end paper and painting. In Wales sheep droppings are currently being tested to determine whether or not they are suitable for making paper. Paper made from elephant dung is also known.

Paper, board and cardboard are made to 60– 95% from fiber materials. Filler and auxiliary materials such as sizes and impregnating agents make up the rest, primarily in order to create various surface effects. Whereas previously, rags were the main base product in paper production, cellulose is now mostly sourced from timber. As cellulose fibers can be used five to seven times for paper production, around 65% of the entire requisite fiber supply is now extracted from waste paper. At around 90%, the proportion of waste paper is at its highest in packaging paper. While newspaper today contains up to 70% fiber material, the amount in print and office paper is only around 15%.

89 Recycling materials

Properties  Chlorine free, bleached paper is marked with the quality seal “TCF - totally chlorine free”. The symbol “ECF - elemen­ tary chlorine free” exists for low-chlorine treated papers. Sustainability aspects  fibers can be reused up to seven times // 60 % less energy and water used in waste paper processing

Recycling paper

Material concept and properties

Mario Stadelmann’s “Paper Chair”

Pulp Collection by Jo Meesters

Weight of paper products Paper

< 150 g/m²

Cardboard Board

150-300 g/m²

> 300 g/m²

Besides protecting forests, the advantage of recycled paper is that it is produced using 60% less primary energy and water than is required to generate fresh fibers. As the pigment or printing ink residue is processed simultaneously with old fibers, recycled paper generally looks gray and yellows rapidly. To remove the printing ink residue, a physico-chemical de-inking process is necessary. In a large container, the printed waste paper is mixed with a wash solution of water and various chemicals (e.g., tenside), and pumped full of air. Black foam containing most of the printing ink from the waste paper forms on the surface. It is siphoned off and subsequently disposed of. Bleaching often follows the de-inking process. Whereas previously chlorine was the primary bleaching agent, nowadays oxygen, ozone and hydrogen oxide are preferred. For environmental paper with 60–70 degrees of whiteness, the bleaching process is foregone. Paper made from the short fibers contained in waste pa-

per is less stable and tear-resistant than that made from fresh fibers, which are long. Accordingly, to produce higher-grade papers, short fibers must be extracted. To attain higher degrees of whiteness, the manufacturers add fresh fibers. The use of waste paper is disadvantageous insofar as it may contain traces of formaldehyde or phenol. use

Recycled waste paper is used in a variety of paper products and packaging materials in which a clear white color plays no major role. Waste paper is also the source material for the production of cellulose insulation systems and bioplastics. In recent years honeycomb cardboard panels have become as important for designers as the use of papier maché (pulp made from waste paper) as a malleable volume. The paper is broken down in water then the pulp pressed and air-dried. Mario Stadelmann’s “Paper Chair” and Jo Meesters’ Pulp Collection are excellent examples.

Products

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PaperStone This panel material for the furniture industry is produced largely from cellulose fibers in waste paper and a natural phenol resin from the shell of cashew nuts. The rest of the material is sourced from ecologically controlled timber cultivation. Its mechanical stability is similar to that of conventional timber materials and it can be processed using the same techniques.

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Environ biocomposite The reinforcement materials for Environ biocomposite are produced from recycled newspapers and bonded by organic resins made from soy protein. Blending them with additives produces panels for the furniture industry, in various colors and marble effects.

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™

Homasote An entire range of construction products made entirely of recycled waste paper is produced under the brand name Homasote . It includes panels and heat insulation systems for walls and flooring, as well as sound insulation solutions.

™

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isolcell  This heat and sound insulating panel is composed mainly of cellulose fibers. There is a layer of plastic on the rear. isolcell is available as felt in rolls with a density of 25 kg/m3 or as a panel with higher densities of between 40–80 kg/m3. As no environmentally harmful additives are used, the material can be fully recycled following disassembly. Given the simplicity with which it can be installed, the material can be used both in new buildings and for renovating existing buildings.

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Papercrete Papercrete is a stone material comprising cement, clay and sand, as well as up to 50% waste paper fibers. It is pressed into bricks, blocks, and panels and can be used in the construction industry for a variety of applications. Besides use in pressed building components, it can also be applied directly to walls as gunned concrete, also known as shotcrete. Given its relatively low weight and high elasticity Papercrete is particularly suitable for buildings in areas at risk from earthquakes.

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90 Recycling materials

zBoard This panel material is a compound of waste paper fibers and MDF. It weighs 62% less than chipboard of equal thickness, and is supplied by the producers in the form of furniture assembly kits and as a construction material with sound and heat insulating properties. zBoard can be fully recycled after use. Given its low weight it is extremely simple to assemble. Panels are joined together by adhesive strips.

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wellboard  A lightweight and particularly flexible panel comprising 100% cellulose and containing neither adhesives nor binding agents is sold under the brand name wellboard . Despite its low weight, it is highly stable and suitable for shops, trade fair stands and furniture. Various profile types weighing from 1.25–2.7 kg/m3 and with corrugation heights ranging from 4.4–8.5 mm are available. The material is highly sensitive to fluctuations in room humidity, and therefore difficult to tailor to exact requirements.

wellboard ®

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zBoard

Recycling of paper (Source: ALBA DASS Betriebs GmbH)

Waste paper and used cardboard packaging

Fraying

™

Removal of foreign materials

Processing

Newspapers, cartons, envelopes, base paper rolls Papercrete™

91

Recycling paper environmental protection symbols

Blue Angel The Blue Angel eco-label signifies recycled paper made to 100% of waste paper. At least 65% is sourced from low grade, middle grade and high-strength waste paper. For a high degree of whiteness, no optical brighteners such as chlorine may be used. Furthermore, no coloring agents containing mercury, lead, cadmium and chrome VI compounds may be used. Limit values were set for formaldehyde (1.0 mg/dm2), PCB (4 ppm) and glyoxal (1.5 mg/dm2).

be part of the production process. Bleaching is also forbidden. Low water consumption must be assured. Ökopa plus This environmental eco-label also indicates the use of “white” recycled paper made to 100% of waste paper, and imposes far stricter criteria than the Blue Angel. Bleaching and de-inking processes are ruled out. Instead, an environmentally friendly white color of a quality equal to that of white paper made of new fibers is attained by surface sizing the paper with natural compounds.

Recycling materials

UWS (“Original environmentally friendly paper”) This eco-label imposes more stringent criteria than the Blue Angel. Only waste paper can be used in the production of paper designated UWS. Neither physical nor chemical extraction of the printing ink contained in the waste fibers may

Bales of waste paper (Source: Isofloc Wärmedäm mtechnik GmbH)

FSC The Forestry Stewardship Council has set itself the task of promoting sustainable usage of natural resources while simultaneously taking account of social, ecological and environmental factors. Forestry operations and timber products can be certified on the basis of ten fundamental principles. These range from protection of the rights of indigenous peoples and the promotion of economic efficiency, through to the implementation of management plans.

Comparison of various types of environmental certification

Name

Blue Angel

nordic swan

eu Eco-label

FSC Recycled

FSC 100 %

FSC Mix

Proportion of waste paper

100 % waste paper, of which 65 % low and medium sorts

not specified

not specified

100 % waste paper no limitations on types

100 % fresh fiber

x % (< 100 %) fresh fiber FSC of controlled origin, can contain y % postconsumer recycled material

Certified forestry

not relevant

at least 20 %

at least

not relevant

yes

yes (materials of controlled origin can be blended)

Use of bleaching agents

no chlorine or halogenated bleaching agents

no chlorine

no chlorine, halogenated bleaching agents allowed

not specified

not specified

not specified

Chemicals: limited ingredients

yes

yes

yes

no

no

no

Chemicals: certain chemicals ruled out

yes

yes

yes

no

no

no

Laser printing emissions limited (VOC/SVOC)

yes

no

no

no

no

no

Limited energy consumption

no, but guaranteed, as recycled paper

yes

yes

no, but guaranteed, as recycled paper

no

no

Limited water consumption

no, but guaranteed, as recycled paper

yes

yes

no, but guaranteed, as recycled paper

no

no

Running qualities specified

yes (EN 12281)

no

no

no

no

no

Aging resistance

DIN 6738, LOK 24-85

no

no

no

no

no

Verification through

Self-disclosure, testing institutes and manufacturer declaration

Self-disclosure and manufacturer declaration

Self-disclosure and manufacturer declaration

external certification

external certification

external certification

15 %

92 Lightweight construction and insulation materials

Honeycomb Structures…096 — Double-webbed Panels…097 — Stainless Steel MicroSandwich…098 — Carbon Fiber Stone (CFS)…099 — Ultra High-strength Concrete…099 — Basalt Fiber-reinforced Materials…101 — Plastics Refined with Mineral Particles…102 — Ceramic Foam…103 — Metal Foam…104 — Wood Foam…105 — Paper Foam…106 — Cellulose Flakes…106 — Natural Fiber Insulation…108 — Rigid Polyurethane Foam…110 — Vacuum Insulation Panels…110 — Aerogel…111 — Hollow Sphere Structures…113 — Technical Textiles…114 — Spacer Textiles…115 — Membrane Textiles…117 — Nanotextiles…118 — Carbon Nanotubes (CNT)…120 — Self-reinforced Thermoplastics…121

— 04 —

93 Lightweight construction and insulation materials

94 Lightweight construction and insulation materials

The use of lightweight materials in architecture and design has become a decisive parameter in optimizing energy requirements. Low material volumes can help reduce construction expenses, simplify assembly, and significantly reduce the energy required for transportation. Self-reinforced thermoplastics and natural and basalt fiber-reinforced structures are some of the recent solutions devised to counter constantly rising energy consumption. In addition to the light construction aspect, foam constructions based on wood, metal, and ceramic offer potential for sound insulation, and with their enclosed air chambers they often have low thermal conductivity. The selection of suitable insulators has become a pivotal factor in the construction of zero-emission and even plus energy buildings. Natural fiber insulation materials and cellulose floc are definitely worth more careful consideration, though primarily hard foam materials based on polyurethane and vacuum insulation panels boast insulation qualities unattained by any other insulation material. One new innovation in the field of transparent heat insulation is aerogels: solid materials with 95% cavities. The enclosed air gives it the best insulation properties of any known material. The structure has a very low refraction index and is highly transparent, which makes it suitable for transparent applications not formerly possible with highly effective insulation materials. Components derived from hollow metallic spheres are another interesting innovation with potential for light construction and heat insulation. Given the enclosed air chambers and the unusually large inner surface, hollow spherical structures are also destined to become heat shields and crash absorbers in vehicle construction.

95 Lightweight construction and insulation materials

Velodrome with metal mesh facade (Source: Velomax; architect: Dominique Perrault)

Lightweight bridge with fiberglass-reinforced concrete (Source: Hessisches Landesamt für Straßen- und Verkehrswesen)

Transparent heat insulation with aerogel core (Source: Cabot Nanogel)

Structures reminiscent of honeycomb are of immense importance to the lightweight construction industry. Even paper in a honeycomb sandwich structure can be used in technical contexts and in unusual architectural and aircraft construction applications.

96 Lightweight construction and insulation materials

Properties  low weight // high mechanical strength // very rigid // heat-insulating // sound-insulating Sustainability aspects  low material use and high rigidity // naturally degradable when bio resin systems used

Material concept and properties

Honeycomb structures – also known under the brand name Honicel – have a very light honeycomb core as their middle layer, to which two thin covering layers are applied. In particular paper honeycombs saturated in resin boast excellent light construction properties. They achieve the fire prevention standards required in interiors and in air transport and, given their sandwich construction possess a high level of mechanical strength and rigidity. Cardboard honeycomb panels or honeycomb with wooden covering layers are made from natural fibers. The air volume enclosed in the cavities gives them a very low surface weight ratio and makes them extremely pressure-resistant. Cardboard honeycomb panels just 20 mm thick can bear a load of 400 kg over an area of 100 cm2. They also have a heat-resistant and noise-insulating effect.

®

Honeycomb structures ®

use

TorHex  TorHex  paper honeycomb cores can be produced as cut-to-size sheets or infinite rolls and subjected directly to further processing. The honeycomb cores can be combined with diverse covering materials (e.g., natural fiber reinforcement layers) and have many potential applications.

Honeycomb structures are of great importance for reinforcing plastic components and as a lightweight core. Ship hulls, aircraft seats, aircraft wings, truck bodies and roof structures are typical industrial applications. The insulating properties are useful for door fillings, wall cladding and in the construction of motor homes. Other uses are in trade fair stand, stage and furniture construction.

Eurolight  This industrially produced lightweight building panel consists of a high-strength very rigid middle layer of hexagonal honeycomb cardboard and a covering layer of 8 mm thick chipboards. The structure minimizes the weight while maintaining rigidity and stability. The panels are used in furniture manufacture and for interior fittings.

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®

Lightweight structure made of paper honeycomb panels (Source: formvielfalt)

Products

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BeeCore  This honeycomb structure, which can be combined with various covering layers, is highly pressure-resistant, energy-absorbing, and offers excellent lightweight construction potential. Using recycled paper for the honeycomb structure means the material has an extremely good energy balance. Beeboards are used in the building industry, vehicle manufacture, packaging and furniture making.

Panel material with honeycomb structures (Source: Econcore TorHex ®)

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Plascore  In lightweight sandwich boards, aluminum honeycomb cores offer excellent stability and corrosion-resistance for industrial applications as well as in aviation and space travel.

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Flamexx  decotech This paper honeycomb structure was developed especially for industrial applications and for use in the building industry. It adheres to the B1 fire prevention class. Honeycomb structures are available in various weights for individual applications. The honeycomb core is made from recycled paper and combined with cover layers of plastic, wood, and other materials.

®

SwissCell  SwissCell  is the name of a honeycomb structure made of cellulose fibers saturated in a special resin, which are compressed into a homogenous material that reveals extraordinary properties under high pressure and temperature. It is particularly suitable for walls, roofs, cars and furniture.

Structure of a cardboard honeycomb panel with wood covering layer (Source: Egger Holzwerkstoffe)

97

Structure of a Beeboard

Honeycomb 135 g/m²

Lightweight construction and insulation materials

Top 365 g/m² Thickness 0.5 m m Production and processing of Eurolight ® (Source: Egger Holzwerkstoffe)

In recent years sandwich panels with translucent plastic boards as cover material and a structural core have become very interesting for architects and designers on account of their appearance and high load-bearing capacity. For some time now they have also been available in biodegradable synthetic resin.

Properties  translucent look // light weight // high load-bearing capacity // UV-resistant Sustainability aspects  manufactured from natural raw materials // biodegradable

Material concept and properties

Architectural panels mostly consist of two 2 mm thick UV-resistant polycarbonate or PMMA covering layers, which give the middle structural layer the required rigidity, a translucent appearance and slip-proof qualities. Polylactic acid (PLA) is used to replace classic thermoplastics and makes the material compostable. Having been used for temporary architecture it can be recycled with no emission of CO2. No toxic waste is created.

Double-webbed panels

Use and processing

Architectural panels are used in advertising, interior fittings (e.g., as partitions, sliding doors and illuminated ceilings) in trade fair stand and furniture construction, and as backlit wall and display elements. Highly resilient versions can also be used as flooring panels. The material can be processed using normal wood and metal processing techniques. When milled, sawed, and bored, the best results are achieved at high cutting speeds. Small surface irregularities can be sanded or polished away. It can be molded when heat is applied (thermoforming).

Composition of a plastic structural panel (Source: Bencore) 1. Covering layer: Polycarbonate or PETG

2. Adhesive

3. Core: Aluminum honeycomb

4. Adhesive

5. Covering layer: Polycarbonate or PETG Marvel bioresin (Source: Marvel GmbH)

A metallic sandwich structure with unique lightweight construction properties for the aircraft and vehicle industries is marketed under the name Hybrix®.

98 Lightweight construction and insulation materials

Properties  1-2 mm thick board material // half the weight of comparable sheet stainless steel // high mechanical stability // enclosed air cushion // weatherproof Sustainability aspects  lightweight building potential for aviation and vehicle industries // also potential for heat insulation

Stainless steel micro-sandwich Trolley made of stainless steel microsandwich (Source: Lamera)

Material concept and properties

The 1–2 mm thick composite material consists of two stainless steel covering layers held together by millions of microscopically small steel fibers, making the material only half the weight of other sheet stainless steel. The density is a mere 1.5–3.9 kg/m2. Given its high level of mechanical stability, the stainless steel micro-sandwich is extremely robust against external influences. Moreover, it does not corrode. Use and processing

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Hybrix  was conceived for all classic lightweight construction applications. The material’s advantages are particularly evident in the case of interior fittings for aircraft. By way of example, refrigerators and serving trolleys for the aviation industry have already been designed in the material. Other areas of application are suitcases, housing for electronic devices, furniture and shop interiors. Hybrix  is comparable with other aluminum laminate materials (e.g., Dibond) as it can be processed using conventional techniques. It is easy to mold, deep draw and bend, which also makes it suitable for containers. It is cut using the usual machining techniques. Individual shapes can be cut with water jet and laser cutting facilities.

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Structure of Hybrix ® (Source: Lamera)

The company Technocarbon can now make granite pliable. Carbon fiber stone (CFS) is the name of a granite (core) composite material that is sheathed in a carbon fiber laminate.

99 Lightweight construction and insulation materials

Properties  pliable, high breaking strength // high compression elasticity // vibration-reducing // light weight (density 2.7-2.9 g/cm³) // low thermal expansion Sustainability aspects  lightweight building properties // vibration-reducing properties

Material concept and properties

The carbon fiber laminate offers protection from extreme strain and ensures the stone does not break even when subjected to shocks. The sheath material makes it highly elastic. It can be bent without damage and afterwards returns to its original shape. The compression elasticity of carbon fiber stone is comparable with that of steel materials. It also boasts vibration-limiting properties, which makes it interesting for a whole range of dynamic applications. The specific weight of CFS ranges from 2.7–2.9 g/cm3, depending on the type, and is comparable with that of aluminum. It barely expands when heated. Use and processing

The special material qualities of carbon fiber stone are particularly interesting for dynamic applications. Possible uses include structural elements for car bodies or machine components where thermal

Carbon fiber stone (CFS) expansion is not desired. The material’s flexibility could possibly be used for crash safety purposes in passenger compartments. The vibration-free behavior makes it suitable for the rotary blades of wind power plants and sporting equipment. It features other beneficial qualities for furniture production and architecture. CFS can be cut using jets of water. Individual parts made from this composite material can be glued. Cross-section of carbon fiber stone (Source: Technocarbon)

Stone materials are among the oldest materials there are that are used for making everyday objects and constructing buildings. So it is all the more surprising that in recent years classic building materials such as concrete have been inspiring designers to come up with unusual ideas for products.

Properties  high packing density // reduced cement content // increased compression stability // lower costs // highly resilient Sustainability aspects  material efficiency // CO²-reducing potential

Ultra high-strength concrete Material concept and properties

High packing density of ultra high-strength cement (Source: g.tecz)

Whereas to date concrete has been used for solid objects, whose formal language is strongly limited by a minimum wall thickness, today completely different results can be achieved with ultra high-strength concrete. Thanks to special mathematical modeling procedures, the optimum particle density can be set for the particular

application. By adapting the cement content the water film density can be significantly reduced by up to 40%. The compression strength is considerably increased. The use of costly additives is unnecessary and material costs are reduced by up to 35%. Ultra high-strength concrete has enormous CO2-reducing potential. Moreover, the higher packing density raises resistance to external influences.

Use

Using a combination of high-performance concrete and a special coating, the designer Alexa Lixfeld was one of the first to succeed in breaking down the barriers and making the material suitable for use as filigree components in kitchen and bathrooms. She achieved finishes that shine permanently and are abrasion and acid-proof, foodsafe and water-repellent. Other examples of use are concrete wall coverings by Doreen Westphal and furniture by Gregor Zimmermann.

100 Lightweight construction and insulation materials

Concrete tableware (Source: Alexa Lixfeld)

Concrete with water-repellent properties (Source: g.tecz)

Concrete wall covering (Source: Doreen Westphal)

At the International Motor Show in Geneva in 2009 and 2010 the developmental service provider EDAG in particular demonstrated with its “Light Car – Open Source” car concept that fiber-reinforced plastics are being used increasingly as a substitute for metals in vehicle manufacture. It used basalt fibers, which have proved their worth in particular in the construction of wind turbines, in the automotive industry for the first time.

101

Properties  low weight (density 2.67 g/cm³) // resistant to high temperatures // chemical-resistant // rigidity comparable to aramid fibers // high tensile strength

Lightweight construction and insulation materials

Sustainability aspects  naturally sourced fiber material // lightweight construction potential // less energy required than for fiberglass production // recyclable

Material concept and properties

Basalt fibers are extracted from the molten mass of volcanic stone at around 1,450°C and come from a 100% natural source. Their properties depend on the composition of the basalt. The proportion of iron, in particular, determines the mechanical properties important for car manufacture. Basalt fibers are very light, have extremely high tensile strength, are chemical-resistant and can be used in a large range of temperatures. Their rigidity (E-module) is approximately 15%, and tensile strength approximately 30% more than in the case of fiberglass, figures roughly comparable to those of aramid fibers. Less energy is used than in the production of fiberglass. When used in composite materials basalt fibers are not a health hazard.

Basalt fiber-reinforced materials

Use and processing

Basalt fiber-reinforced plastics are used as lightweight replacements for metallic materials in the aviation, automotive and building industries. They are also used to make tubes, containers and boats, and in the manufacture of wind power generators. Basalt fibers that are 4–6 mm long and have a diameter of 10–13 µm are ideal for processing in thermoplastics. Fabrics, fiber strands, basalt mats and filament yarn are marketed by various manufacturers for further processing.

“Light Car - Open Source” vehicle study (Source: EDAG)

Canoe made of basalt fiber-reinforced plastic (Source: Basaltex)

Basalt fiber fabric (Source: Basaltex)

Molded part made of basalt fiber-reinforced plastic (Source: Basaltex)

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In the development of environmentally friendly plastic packaging and building insulation, producers are at present pursuing quite different goals. While some are focusing on producing polymer materials based on renewable raw materials, (e.g., polyhydroxybutyrate and polylactic acid), others are attempting to reduce the proportion of crude oil-based polymers by introducing mineral additives. At the same time there is also a focus on improving the energy balance in manufacture and recycling, on reducing water consumption, and improving mechanical and heat-insulation properties. In the plastic technology field, incorporating aggregates and additives is referred to as compounding.

Properties  low weight // good mechanical properties // high proportion of natural raw materials // material-saving // improved heat insulation Sustainability aspects  low energy con­ sumption during manufacture // high proportion of natural raw materials // slight thermal conduction

Lightweight construction and insulation materials

Plastics refined with mineral particles

Material concepts and properties 108

126

114

194

111

234

280

360

624

4

280

309

17

24

1,900

2,100

2,900

9,100

13,700

Environmental comparison of different packaging concepts 22

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Calymer One such product is the milk packaging Ecolean, which is used, for example by the eco-village Brodowin for packaging its organic whole milk. It is remarkable not only for its astonishingly low energy balance, but also for the well thought through product design. Ecolean milk packaging consists of 40% natural chalk (calcium carbonate). Combined with recyclable plastic, very light packaging is produced, which, weighing a mere 16 gm per one-liter package, uses less energy and water to produce than other disposable packaging and, moreover, produces significantly less waste. The amount of energy consumed in producing the raw material is some 80% lower than for other packaging materials such as cardboard and PE.

1

2

3

4

5

1

2

3

4

5

1

2

3

4

5

1

2

3

4

5

Gigajoule

Kg

1,000 Liter

Kg

Energy (GJ) required when manufacturing 100,000 packages of 1 liter size

Production waste (Kg) generated when manufacturing 100,000 packages of 1 liter size

Polluted water (1,000 liter) generated when manufacturing 100,000 packages of 1 liter size

Greenhouse gas (Kg) emited when manufacturing 100,000 packages of 1 liter size

1 = Ecolean ® Milk Packaging / 2 = Gable Top (GT) / 3 = GT with Reclose / 4 = HDPE Bottle / 5 = PET Bottle

Neopor ® insulating material with graphite reinforcement

Liquid waste is only 2–4% of the volume otherwise produced and the emission of green house gases during production is also considerably lower. The shape and construction of the package, which was inspired by a carafe, also make it easy to open and pour, while being highly tear-resistant and stable.

Ecolean ® milk packaging

Neopor  Neopor  is the advance on the insulating and packaging classic, Styrofoam . The silver-gray color of the expandable polystyrene (EPS) comes from microscopically small graphite platelets, which are added to the polystyrene. They considerably reduce the thermal conductivity of the material and increase insulating performance by 20%. This decisive advantage plays a role in reducing heating costs and makes buildings more environmentally sound. Foam manufacturers save up to

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50% of raw material while maintaining the same insulating effect and craftsmen are able to work with board material that is up to 30% lighter. There are numerous fields of application for Neopor  . Typical uses include insulating building sheaths, roofs and floors. Formwork blocks can also be made out of Neopor  granulate. Neopor  insulating materials are free of CFC, FCKW, HFKW and other cell gases. Only air is contained in the structure, providing heat insulation properties over a long period of time. Fire behavior is rated class B1 (flame retarding). Processing possibilities are comparable to those of Styrofoam .

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Industrial foam structures were developed to combine the lightness of a sponge with the rigidity of the base material. Foams are made from polymer materials, metal, wood, glass and paper, and material laboratories have been able to develop several products. Ceramic foams are increasingly finding their way onto the market on account of their heatinsulating properties, and have found widespread use in the building industry, heating systems and in space travel.

103

Properties  closed and open-pore structures // resistant to high temperatures // sound-absorbing // optical transparency // large inner surface

Lightweight construction and insulation materials

Sustainability aspects  100 % recyclable // air-purifying // heat-insulating

Material concept and properties

Open-pore foams made of ceramic materials such as silicon carbide account in most cases for the structure of polymer foams and thus combine the permeability and low weight of foam structures with the sound mechanical qualities of ceramics. Ceramic foam can be used in temperatures up to 2,000°C and also boasts acoustic absorption properties.

Ceramic foam

Use and processing

With their potential for thermal insulation, ceramic foams provide opportunities for use in particular for insulating buildings or as heat shields in space travel. Additional applications range from engine manufacture and thermal generators to filter systems for toxic materials (e.g., diesel exhaust filters) Ceramic foams are used in particular in lightweight construction. In sound absorbers they are intended to help reduce aircraft noise. The first products to emerge in the design field are luminaires with an interesting transparent effect.

Dual-component ceramic foam Dual-component ceramic foams were developed in order to manufacture thermal insulation for fire prevention applications in the building industry. At room temperature these foam and harden within 20 minutes without any extra external heat. The resulting ceramic foam is water and steam-

resistant, fiber-free and durable to temperatures of 1,000°C. As dual-component ceramic foams contain no toxic substances they are approved for the food industry. They are also non-flammable (building material class A1).

Products

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Duocel SiC Foam Ceramic foam from ERG Aerospace is porous, has an open-cell structure and is made of silicone carbides. It boasts excellent physical properties, is very heat resistant, has a low flow resistance, and its large enclosed air volume makes it an excellent insulator. Duocel ceramic foams are also used to filter environmental pollutants.

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Foam structure made of silicon carbide ceramic (Source: ERG Aerospace)

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Stelex  The vast majority of worldwide ceramic foam production is used in the casting industry. Casting filters by Foseco are made of aluminum or zirconium oxide and used in the production of high-wear casting and safety components such as brake parts, crank shafts, wheel hubs, suspension brackets, and axle pivots. Casting filters retain slag and the produce of chemical reactions, thereby improving physical properties and considerably reducing the outlay for post-processing.

Lamp with ceramic foam lampshade (Source: Nextspace, serien.lighting)

Some 30 years have passed since the principle behind the manufacture from metallic materials of foams with a bone-like structure was discovered. The great advantage lies in a highly favorable ratio between solidity and mass, as depending on the type and structure, metal foams consist of only 80–90% air. To date aluminum was mainly used for manufacturing metal foams. The sinter production process, however, makes it possible to produce metal foams from almost any metal material such as stainless steel, titanium, or copper.

104 Lightweight construction and insulation materials

Sustainability aspects  fuel-saving through reduced weight // air-purifying properties // sound-absorbing properties

Metal foam

Material concept and properties

With regard to products available on the market, a difference is made between open- and closed-cell foam structures. While closed-cell versions are manufactured using foaming agents, open-cell structures are made either by casting or sintering. The sintering technology is based on a plastic sponge, which is coated with a metal powder and binding agent suspension. The polymer material is then debindered at 300°C and the metal sintered. What remains is an air and liquid-permeable structure with interesting optical qualities. In addition to high rigidity, metal foams boast good cushioning and sound and heat-absorbing qualities while the large inner surface also makes them useful for purifying air.

Properties  closed and open-pore structures // all metal materials possible // high rigidity // impact-resistant // optical transparency // large inner surface

Use and processing

Given the lightweight construction aspects, metal foams are primarily suitable for vehicle manufacture (truck mountings, open tops, tram carriages). The good shock-absorbing characteristics also make them valuable as crash absorbers and moving parts. Other applications are soundabsorbers, heat exchangers, catalytic converters and filter systems. Their optical qualities make them especially interesting for trade fair stands and luminaires. Metal foams can be processed with conventional processing techniques such as sawing, milling and turning.

Products

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foamet foamet is the name of an open-cell metal foam made by means of powder-metallurgy processes based on a plastic sponge. This forms the desired geometry of the subsequent component. foamet metal foams can be made from any metal. Gas and liquids can flow through them and they have a large specific surface and low densities. The cell width of the sponge can be varied from 0.3–5 mm. Porosity can be adjusted between 70–95%.

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Alulight As a result of the production process, the closedpore foam by Alulight  has a casting skin which is just a few tenths of a millimeter thick. It is easily processed and can be sawn, milled, drilled and turned. The mechanical properties can be changed through the density of the foam or the size of the pore. Alulight  aluminum foam is available in densities ranging from 0.4–0.7 kg/dm3 and can be reinforced with a foamed expanded metal or with glued-on materials such as wood veneer, plastics and sheet metal.

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Lamp made of openpore metal foam: (Source: Zoon Design)

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Zincopor  Using expanding agents in a die-casting process produces zinc components with an inner foam structure that is equally as stable and 50% lighter than comparable cast parts. These components with their open-pore surfaces are in use wherever saving material and weight is a priority.

Macro-photo of an open-pore metal foam structure (Source: hollomet)

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m.pore  The open-pore aluminum foams by m.pore  are made in a casting process and based on a PUR foam. Their relative density is approx. 10% for all pore sizes. Flow-through properties depend on the size and number of pores per inch (ppi). Heat exchanger with open-pore metal foam (Source: hollomet)

Trade fair stand using aluminum foam (Source: formvielfalt)

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105 Lightweight construction and insulation materials

Mechanical engineering part made of openpore aluminum foam (Source: ERG Aerospace)

Zinc foam door knob (Source: Zincopor)

The main objective in creating foam from wood is to reduce the weight of the material while retaining the structural resistance. Wood foam can be produced from natural source material without chemical additives.

Properties  porous material structure // very low weight // excellent heat insulation // high stability //noise and shock-absorbing Sustainability aspects  wood foam is watersoluble and the original materials can be reused, e.g., processed into wood pellets // lightweight construction aspects // heat-insulating and sound-absorbing

Material concept and properties

A bio-technical foaming process is used to make an evenly porous structure from pure plant material. Sawdust, wood dust and the hulls of wheat and rice are the starting materials. These are ground finely with the aid of water and starch to make a wood paste to which yeast and bacteria are added (fermentation). The wood mixture swells and is dried and hardened in an oven process into panel formats with a rusk-like finish. The finish is porous with good mechanical strength levels, a very low weight (250–300 kg/m3) and excellent heat insulation properties.

Wood foam

Application and processing

Given their low weight, high stability, and rigidity, not to mention the ecological manufacturing process, panels made of wood foam are suitable wherever a high load-bearing capacity, easy processing and the possibility of easy disposal are required. Wood foam is especially suitable as a structurally resilient core material in the manufacture of wooden composite materials for lightweight construction. Compared with conventional varieties, panels that have undergone a carbonating and ceramization process are very stable and no longer water-soluble once treated. Device holders for hi-fi components made of wood foam ensure a harmonious sound with improved reproduction. They also have a slight absorbing quality. Wood foam can be processed using the usual processing techniques. It can be veneered to a premium standard for use in the furniture industry.

Properties of wood foam MDF board

Chipboard

Fiberboard

Wood foam***

40

ca. 20-50

Thickness in mm

19

40

19

80**

Basic thickness

Kg/m³

732

700

600

520

150-250

226-309

Bending strength

N/mm²

22

18

20

10

practically 0

0.9-1.57

Bending e-module*

N/mm²

3,000

2,700

2,800

1,770

practically 0

146-227

Compression strength N/mm²

10-20

10-20

10-20

10-20

very low

0.59-2.04

0.6-1.0

0.6-1.0

0.35

–

very low

0.07-0.46

Transverse tensile strength

N/mm²

Swelling in thickness % (24h) Equilibrium moisture % Thermal conductivity W/mK Diffusion resistance Specific heat

Wh/KgK

12

8

15

–

–

30.3

11-15

11-15

11-15

11-15

11-15

1.21-1.51

0.1

0.1

0.14

0.1

0.04

0.08

40-60

40-60

80-200

30-50

5

14.29

0.75

0.75

0.75

–

0.7

not clarified

* In the case of boards that are subject to long-term bending pressure the creepage must be taken into account (the fibers or parts of wood materials shift under stress, resulting in lasting curvature) ** “Homogen80”, product specifications *** Figures from the “Fermentation of Wood by means of Yeast” research study conducted by the Department of wood at AHB in Biel, Switzerland

The small cylinder-shaped flakes of paper foam are called “flupis” and are used for packing fragile objects or household devices to protect them during transport. They are produced in an environmentally friendly way from waste paper and sustainable raw materials and in the long term are intended to replace polystyrene, which is normally used for packaging.

106

Properties  substitute for polystyrene // very low weight // shock-resistant // easy disposal // no foaming agents or softeners // can be injection molded

Lightweight construction and insulation materials

Sustainability aspects  based on sustainable resources and waste paper // simple manufacturing process // no chemical additives

Material concept and properties

Waste paper is shredded, ground, mixed with wheat starch and pressed into granulate. Under the influence of pressure and steam this can be foamed into small sausage-like shapes in an extruder or injection molded into molded parts with a soft surface. The production time depends on the size and thickness of the molded parts, varying from a few seconds to two minutes. As no chemical foaming agents or softeners are used in the manufacturing process and it decomposes into its natural components when disposed of, paper foam can be put with normal household waste. Decomposition is accelerated by starch. Paper foam parts can be easily dyed and are made from waste paper.

PaperFoam  . Apple also uses paper foam products to pack MP3 players and notebooks, to protect them from damage. It is also used as insulating material, and is even said to make good cat litter.

use

products

Material paper foam has become especially well known as packaging for CD and DVD trays. These are marketed by a Dutch firm, under the trade name

Flupis  During production, newspaper and cardboard box waste is mixed with natural wheat starch and an alcoholic binding agent and then foamed with the help of water vapor. Depending on the formula, varying degrees of rigidity can be produced with an homogeneous finish. As loose filling material they protect valuable items from being damaged.

Paper foam ®

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Flupis ® made of paper foam (Source: Hellblut)

Even though cellulose flakes have been used as an insulating material since the 1920s their importance has grown only in recent years, in connection with the sustainability debate. Material concept and properties

The material owes its excellent insulating properties (thermal conductivity: 0.038–0.045 W/mK) to air chambers, which are incorporated into the three-dimensional flake structure. In the manufacturing process waste paper is mechanically shredded and the fibers separate. The cell walls

PaperFoam  Molded paper foam parts are produced using the injection molding method. A viscous mass of fibers, starch and water is injected into a mold heated to 200°C, where the water evaporates and acts as an agent to foam the mass.

Packages made of PaperFoam ® (Source: PaperFoam ®)

Properties  based on waste paper // excellent heat insulation // high noise protection // low density: 30-80 kg/m³ // excellent flame resistance // mold resistant Sustainability aspects  very high heatstorage capacity // pleasant ambient climate // alternative to rock wool, polymer foams and glass wool // can be recycled

Cellulose flakes

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become interlaced with one another. Through the addition of borate, ammonium, or aluminum salts (proportion: 8–20%) fire prevention class B1 is achieved. These additives also make the material resistant to mold. In addition to demonstrating a high heat-storage capacity, cellulose flakes have an excellent insulating effect and offer good noise protection. The material does not give off any chemicals, is pervious for steam and regulates moisture (steam diffusion resistance: 1–2). This makes it an ideal insulating material wherever an excellent room climate is also required. However, given the cell structure its ability to withstand mechanical load under pressure is limited.

Lightweight construction and insulation materials

Use and processing

The use as an insulating material for roofs, ceilings, and walls is now widespread. It can either be piled up loosely, sprayed while damp onto vertical walls, or blasted into airtight cavities between an inside and outside wall. It is also used in timber framework buildings. Insulation by blasting machine is an ideal choice for refurbishing old buildings. In addition to being used in the construction industry the material is also suitable for numerous applications, e.g., as a modeling mass in model construction and art. Paper pulp is used for furniture construction.

Cellulose flakes as injection insulation (Source: Isofloc ® Wärmedäm mtechnik GmbH)

Products

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Isofloc  Isofloc  is a heat insulating material for various architectural applications such as sloping roofs, domes, walls, ceilings, and floors. The standard versions contain 8% additives and are assigned to fire prevention class B2. Cellulose flakes that are flame retardant and resistant to mold contain at least 12% additives. If special optical properties are also to be attained, paper that is free of printer’s ink is used to manufacture the flake material.

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Dämmstatt In producing this brand of cellulose flakes, special emphasis is placed on using sustainable resources. Consequently, borate-free insulating material is available.

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fineFloc  Cellulose flakes from Homatherm with thermal conductivity of 0.039 W/mK are suited above all for blast-in insulation. The recyclable material is an economical option wherever thick densities are needed. Other brand names of cellulose flakes are: climacell  and thermofloc 

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Paper chair made of paper pulp (Source: Mario Stadelmann)

Fire prevention capability of cellulose flakes (Source: Isofloc ® Wärmedäm mtechnik GmbH)

Thermal conductivity of various materials Wh/m³K

0

5

10

15

20

25

30

35

Mineral fiber Rock wool Hard foam Sheep wool Isofloc®

Energy needed to produce various insulating materials Product

Mass Volume Gross density (kWh/kg) (kWh/m²) (kg/m³)

Isofloc ® 1.2

50

50

Rock wool

4.7

128

27

Glass wool

8.9

178

20

Wood fiber board

4.2

709

170

Exp. polystyrene

26.4

396

15

Polyurethane hard foam

26.4

834

30

Hemp, cork, wood fibers, sheep’s wool … even though the heat insulation properties of natural insulation materials are not as favorable as for materials based on inorganic materials such as glass- and rock wool or polymer foams (e.g., PUR, EPS and XPS), in terms of resource saving and primary energy they are to be positively evaluated.

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Sustainability aspects  no health-hazardous content // based on renewable resources

Lightweight construction and insulation materials

Materials and use

In the construction industry, insulating materials serve to reduce heat loss through the building’s shell and to produce a pleasant ambient climate in the building interior. Other reasons for using insulating materials include reducing the noise level and preventing climate-related damage caused by damp. In selecting the right heat insulation, the architect or developer determines the amount of heating energy needed for the next 30 to 50 years. Owing to the enormous ecological impact of insulation, the range of different insulating materials available on the market has exploded in recent years. Whereas in 1990 some 17 million m2 of insulating materials were produced, in 2001 this figure stood at over 29 million m2. Mineral fibers such as glass wool and foamed glass continue to account for the largest share, although the importance of natural-fiber insulating materials based on hemp, cork, wood shavings or sea grass has risen in recent years. Hemp Some 85% of hemp insulating materials is sourced from the stalks of the hemp plant. The remaining 15% is accounted for by polyester fibers, which are made into mats and fleeces. The insulating effect is due to the air caught between the hemp fibers. As they offer sufficient thermal conductivity and good sound absorption hemp insulating materials are employed in sloping roofs, light construction walls and floors. Even without additives they are resistant to pest infestation. Impregnation with soda makes for sufficient fire prevention (material class B2).

Natural fiber insulation

Hemp plant (Source: Hock Thermohanf)

Thermal conductivity of various insulation materials Glass wool

0.035-0.040 W/mK

Rock wool

0.035-0.040 W/mK

Foamed Glass 0.040-0.055 W/mK Perlite 0.050-0.070 W/mK

Flax Flax insulating materials are made from the flax plant, which for several years now has been cultivated in Germany again for linen production. The fibers are stuck together using potato starch. Polyester fiber is used as reinforcement. Flax fibers are resistant to rot and to fungal infestation. They are used as insulating strips in roof structures, as insulation between rafters, and in floor and ceiling constructions. Fire prevention class B2 is attained through the addition of ammonium sulphate or borate salts. Cork Cork comes from the bark of the cork oak. Its prime insulating and water-repellent properties

Wool insulation (Source: Villgrater)

PUR hard foam

0.025-0.030 W/mK

Polystyrene particle foam (EPS)

0.035-0.040 W/mK

Polystyrene 0.035-0.045 W/mK extruded foam (XPS) Hemp

0.045 W/mK

Flax 0.040-0.045 W/mK Cork 0.045-0.055 W/mK Sheep’s wool

0.035-0.040 W/mK

Softboard 0.040-0.050 W/mK Wood wool 0.065-0.090 W/mK Meadow grass

0.040 W/mK

Sea grassfill 0.043-0.045 W/mK Neptune balls

0.037 W/mK

Vacuum insulating panels 0.004-0.010 W/mK

Insulating mats made of hemp fiber (Source: Hock Thermohanf)

result from its web-cell structure, which contains air. The insulating substance suberin occurs in the cell walls. It is a poor conductor of electrical currents and relatively resistant to fire and to wear and tear. No additives are required to comply with building material class B2. In addition to the usual indoor and outdoor insulation applications, thanks to its high compressive strength cork can be employed beneath concrete as impact sound insulation.

109 Lightweight construction and insulation materials

Sheep’s wool Sheep wool insulating mats are made of sheep’s wool reinforced by polyester fibers. Gross density is between 15–60 kg/m3. Thanks to its excellent sound absorption, sheep’s wool is ideally suited for acoustic ceilings and walls. As an insulating material sheep wool mats can be used both between and below rafters in roofs as well as for the interior insulation of outer walls.

Softboard holzFlex ® with textile fiber from cornstarch (Source: Homatherm)

Wood wool Wood wool, lightweight panels are made by adding a mineral-based binding agent such as cement. This lends the insulating material flame-retardant properties (building material class: B1). The wood wool is primarily gained from fast growing timber (e.g., fir, pine). As wood wool lightweight panels usually offer only moderate heat insulating properties they are normally available in conjunction with other insulating materials. Lightweight panels based on wood wool are used outside to prevent thermal bridges, and are employed in sound-absorbing suspended structures.

Sea grass Sea grass is a collective term for the plants that grow in almost all oceans at a maximum depth of 15 meters. Centuries ago, sea grass was already being used as an insulating material on the North and Baltic Sea coastlines. With relatively low thermal conductivity it has been gaining in importance again over the past few years. Sea grass is a 100% natural construction material and can be used as protective insulating material or as fiber panels for interior and intermediate rafter insulation. It is considered flame-resistant and is mold-resistant.

Sea balls What are commonly referred to as Neptune balls, which are made of matted seaweed fibers, can also be used without additives as an insulating material with natural fire prevention properties (B1). The organic brown material can be found washed up on beaches. As it contains hardly any salts and no proteins it does not rot and the fibers are not harmful to the human organism. With thermal conductivity of just 0.037 W/(mK), sea balls are highly suitable for building insulation (e.g., in roofs and timber structures.) They are sold as a commodity under the brand name NeptuTherm  .

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Soft wood fibers Softboards are made from the waste products from sawmills. These products are ground, water is added to produce a pulp, and this is then dried at high pressure. Natural resins provide an enduring binding agent. Thicker panels are made by adding casein glue. The panels can be made damp-resistant by adding bitumen or latex emulsions. Soft wood fiber panels are primarily employed in sloping roofs, to provide sound impact insulation, or to insulate walls on the inside and outside. Meadow grass The good thermal insulation profile exhibited by insulating materials made from meadow grass can be attributed to the latter’s cellulose content. Furthermore, it is CO2-neutral, biodegradable and inherently stable. To make the material suitable for fire prevention purposes, 5% borax is mixed with the cellulose fibers. It is used as insulation foam or ballast in flooring and walls. Moisture has a negative effect on the material’s insulating properties.

Processing of natural fiber insulating mats (Source: Hock Thermohanf)

Neptune balls on Sicily’s beaches (Source: Neptutherm ®)

Although rigid polyurethane foams are produced on the basis of crude oil, they can nevertheless lay claim to possessing sustainable aspects, as rigid PUR foam panels have the lowest level of thermal conductivity of all insulating materials on the market. The same level of insulation is possible with constructions that are up to 40% thinner. This makes them particularly attractive for refurbishing existing buildings, and as interior insulation in small rooms with low ceilings.

Material concept and properties

PUR foam is the result of a chemical reaction between polyol and isocyanate. Through the addition of foaming agents and catalysts under the influence of water vapor, the product is subsequently foamed to volumes of between 20–50 times larger than its original size. A thermoset, closed-cell hard foam emerges, possessing thermal conductivity of just 0.025–0.035 W/mK. Rigid PUR foams are resistant to chemicals and solvents and, with the addition of flame retardants, they correspond to fire prevention classes B1 and B2. The production of polyols from castor oil has recently become possible, and we can therefore expect to see a long-term reduction in the use of fossil fuels as a PUR feedstock.

110 Lightweight construction and insulation materials

Properties  closed cell structure // very low level of conductivity // slender insulation constructions // fire prevention class B1 possible Sustainability aspects  very good insulation properties // material-efficient con­ structions // polyols based on castor oil possible

Rigid polyurethane foam tion of exterior walls. These can be used both for perimeter insulation as well as for park decks and roof terraces. As a result of their outstanding heat insulation properties, high-performance polyurethane insulating materials are accounting for a

steadily increasing share of the overall insulation market. Over a life cycle of 30 years they save more than eighty times as many CO2 equivalents as are associated with the production, transportation and processing of the material.

Hard polyurethane foam panels being processed (Source: Bayer MaterialScience)

Polyurethane foam panels for floor insulation (Source: Bayer MaterialScience)

Use and processing

The main fields of use for hard polyurethane foam panels are roof, wall and flooring insulation, both indoors and outdoors. Compound systems with a high degree of stability are available for the insula-

Properties  outstanding insulation properties // lean insulation constructions // shock-sensitive // high costs Sustainability aspects  high level of insulation and lean design // reduction in the amount of material used

Alongside the use of insulating materials, over the past few years structures have been developed which, by exploiting the insulating properties of the vacuum, possess a thermal conductivity ten times lower than conventional insulation materials such as glass wool and polystyrene foam. Material concept

Vacuum insulation panels

Using a porous filling material as a spacer, a vacuum is produced in a sheath construction and subsequently sealed. On the outside it is protected by an air and diffusion-proof layer. Its low level of thermal conductivity (between 0.004– 0.010 W/mK) can be attributed to the low mobility of the remaining air molecules in the vacuum. Heat exchange is reduced to a minimum. For this reason the panels are considerably more lean than customary insulation systems.

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Lightweight construction and insulation materials

Use and processing Vacuum insulation panels with metallic high barrier film (Source: Variotec)

Vacuum insulation panels are always used in the refurbishment of existing buildings whenever there is insufficient space for conventional insulation solutions. Since the panels react highly sensitively to the application of force, they are also for the most part placed in polystyrene foam.

Variotec VIP A multi-layer, metallic high barrier film seals the silicic acid protective core, which is in a vacuum, ensuring it airtight and diffusion-proof. Between 10–40 mm thick, Variotec  panels offer a high level of insulation. Building authority approval is still pending such that any use must be approved on a case-by-case basis.

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LockPlate  These vacuum insulation panels are comprised of a supporting porous core surrounded by a film that is impervious to gas. In this way, pouches emerge which can be evacuated and sealed to just a few millibars. A mere 9–11 cm in length, they deliver extremely high insulation levels. The LockPlate  system is suitable for retro-insulating old buildings.

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Vacuum insulation panels on a building site (Source: Saint-Gobain Weber GmbH)

With a cavity component of over 95%, Aerogels have been entered in the Guinness Book of Records as the solid with the lowest density. This is attributable to their spongy solid body structure, consisting largely of air, which makes the material the best there is for insulating purposes. As a result of its foam-like structure, people also refer to it colloquially as “frozen smoke”.

Properties  lowest density of all materials (0.2-0.5 g/cm³) // high transparency // low level of thermal conductivity (heat coefficient: 0.008-0.017 W/mK) // large interior surface // high absorption capacity // incombustible Sustainability aspects  outstanding heat insulation qualities // sound-insulating properties // extremely low weight

Material concept and properties

The particular qualities of aerogels are attributable to their mesh of solids with porous spaces of at most 20 mm. The enclosed air molecules can neither move around on a large scale nor, when resting, can they oscillate. At 1,000 m2/g, they have an unusually large inner surface. Alongside their structural specifics, their visual qualities are also particularly remarkable, as aerogels display a very low refractive index and are highly transparent. UV light does not result in any undesired discoloration. Aerogels are not inflammable and only melt at a temperature of 1,200°C, are breathable, and conduct heat as well as sound waves extraordinarily poorly.

Aerogel

Aerogel structure (Source: Cabot Nanogel)

Transparent heat insulation for industrial buildings (Source: Cabot Nanogel)

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Use and processing

As a result of their large interior surface, aerogels are used as filtering and insulation materials. In architecture, they are primarily used as transparent insulation panels, as additives in glass elements, roof structures and double-walled panels. Furnace monitoring windows are ideal for fitting with aerogels. Their low refractive value also makes them ideally suited to radiation detection. Material scientists are currently conducting research into their potential as catalytic converters and fuel cells. Aerogels are mostly available in the form of a granulate that can be poured, does not settle and can be processed seamlessly.

material behind clinker brick facades. Further­ more, Nanogel offers a high level of heat protection, even in the case of thin layers.

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Okagel Architectural glass manufacturer Okalux uses translucent aerogel made by Cabot between its products’ glass panes and has launched an insulating glass called Okagel , which is intended to be put to energy-efficient use in museums, sports facilities and administration buildings. It displays G-values that, unlike those of conventional gasfilled insulating glass, are independent of the angle at which they are installed. With a 60 mm intermediate layer of Nanogel, the corresponding G-value is even less than 0.3 W/m2K, fulfilling passive house standards. Double glazing with 30 mm of Nanogel in the intermediate areas has a G-value of 0.6 W/m2K.

Lightweight construction and insulation materials

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Products Web panel filled with aerogel (Source: Bayer Sheet Europe)

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Nanogel Under this brand name, Cabot Nanogel GmbH manufactures a highly porous, translucent silicon aerogel with high insulating, water-repellent and mold-resistant properties. As it is available in granulate form, Nanogel can be used as a high-performance insulating material for subsequent injection in particularly narrow cavity layers from a thickness of 1.5 cm. This makes the material suitable for the core insulation of dual-skin outside masonry and as an insulating

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Makrolon  Ambient These are polycarbonate web panels filled with aerogels that boast extremely high heat-insulating qualities, high translucence and optimum light diffusion when used as roof glazing. With a G-value for the glass of 1.0 W/m2K, they deliver insulating qualities comparable to triple glazing. An extra thick exterior layer, improved UV protection and transparent bridges complement the material’s performance characteristics.

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Flexible insulation with nano-porous aerogel (Source: Aspen Aerogels) Okagel ® G-value U-value [W/m²K]

U-value [W/m²K]

2,0

2,5 6 mm

1,8

Nanogel filling

1,6

Air 16 m m

2,0

1,4 1,2

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Pyrogel Pyrogel is a flexible insulating material made from nano-porous aerogel with carbon and fiberglass reinforcement. It can withstand temperatures of between -40 and +650°C and is thus suitable for fireproof lagging for pipes and for insulating 3D surfaces.

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Argon 16 m m Krypton 10 m m

1,5

1,0 0,8

1,0

0,6 0,4

OKAGEL 30 m m

0,5

OKAGEL 60 m m

0,2 0,0

0,0 0

10

20

30

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Nanogel filling in m m

90° 75° 60° 45° 30° 15° 0° Fitted inclination (90° = vertical)

G-value over space between panes when Nanogel filling is used (Okagel®)

Structure of a pane of glass with an intermediate layer of aerogel (Source: Nanobau) Glass

Light transmission and G-value following DIN EN 410

Gas 12 mm

0,7

Twin-wall sheet

Glass High-insulation glazing for a polar research station (Source: Okalux)

Gas 12 mm

0,6 0,5 0,4

Shattered light

G

0,3 Lt vis

0,2 0,1 0,0 0

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Low-ecoating

Granulate-shaped silica aerogel

Low-ecoating

A production process developed in recent years on the basis of sinter manufacturing principles makes it possible to produce structures based on hollow metallic and ceramic spheres. These are already in use in an industrial context but not, as yet, in either design or architecture.

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Properties  compact hollow structure // compression-proof and rigid // almost every metallic and ceramic material possible // high level of insulation // qualities dependent on shell thickness and porosity // shell thickness: 10-100 µm // diameter: 0.8-20 mm

Lightweight construction and insulation materials

Sustainability aspects  100 % recyclable // fuel reduction through use of the lightweight elements in vehicle construction // heat and noise-insulating

Material concept and properties

These high-strength hollow spheres offer an option for flexibly filling non-rigid geometrical shapes. They are produced on the basis of EPS spheres. In an air-suspension coating process, these are coated in a suspension made from metal or ceramic powder, binding agents and water, and subsequently heated. The polymeric material evaporates, and what remains are hollow spheres made of metallic or ceramic material. Thanks to this production principle, any material that can be sintered is suitable for processing. The material’s properties can be influenced as regards the thickness and porosity of the outer surface as well as the base shape. On account of the high porosity and the many surfaces that interact, the thermal conductivity of hollow spheres is considerably lower than that of solid materials. To achieve particular properties, other materials can be injected into the existing hollow sphere. Given the geometry of the sphere, hollow sphere structures boast pressure-resistant and rigid characteristics. Hollow spheres are 40–70% lighter than solid-state ones.

Hollow sphere structures Products

The production and processing of hollow sphere structures was developed at the Dresden branch of the Fraunhofer Institute for Manufacturing and Advanced Materials (IFAM) in collaboration with Glatt GmbH. They are at present made from various metallic and ceramic materials and sold under the brand names globomet  and globocer  . Highly stable sandwich elements are used primarily in

mechanical engineering. Their crash-absorbing potential is particularly interesting for vehicle manufacture. Using hollow sphere structures can result in enormous weight reductions and yet ensures high stability – useful for aerospace technology. The lightweight aspects also make hollow spheres suitable for use as prosthetics.

Hollow sphere structure as panel material (Source: hollomet)

Cavity balls stuck to a pipe (Source: hollomet)

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As a result of their particularly high insulating properties, hollow sphere structures are suitable as heat shields in furnace construction. The large interior surface and the noise and oscillationreducing qualities also make them interesting as heat exchangers, catalytic converter elements, crash absorbers, sound absorbers, and lightweight reinforcement elements. Since the material is virtually unknown in architecture and design, there are still no uses in these fields. In particular the possibility of using it for filling hollow spaces to produce a stabilizing effect is interesting for mold making. Its aesthetic qualities suggest potential uses in jewelry design. Hollow sphere structures are produced either by lightly pressing hollow spheres in a mold and then sintering or sticking them. The use of robots makes the production of defined geometric structures possible. Hollow sphere structures can be processed using conventional machining techniques.

Production process of hollow spheres and hollow sphere structures

Styrofoam

EPS

Design

Coating

Green spheres

Heat treatment (debinding, sintering)

Hollow sphere structures

Hollow spheres

114 Lightweight construction and insulation materials

Metallic hollow spheres (Source: hollomet)

Ceramic hollow sphere under the microscope (Source: hollomet)

Textiles have long been more than just a simple material and now, thanks to new chemical, thermal and mechanical properties, they are revolutionizing architecture and vehicle manufacture. Opportunities for the innovative use of textile materials are generating new approaches that take our classic conceptions to absurdity: vehicles now have a flexible skin, buildings a changeable structure, and folding tent systems are being prepared for use on the moon. Material concepts and use

Textile mobility GINA stands for “Geometry and Function in N Adaptions”, and refers to a vehicle concept developed by BMW, which has no metallic bodywork but is covered instead by a textile skin made of polyurethane-coated Lycra. This consists of a stabilizing backing mesh and a water-resistant hybrid fabric that is equally resistant to the cold and to heat, and absolutely waterproof. The vehicle looks as if it was shaped in a single mold, with functional elements that become visible only when they are needed. If the driver switches on the lights, the headlights open like an eyelid; if a GINA needs to be cooled down, the bonnet material simply moves to one side. Costs are optimized also by the textile outer skin: the silver drape consists of only four – instead of the regular ten – bodywork parts, and can be wrapped around the aluminum structure in two hours. Furthermore, no painting process is necessary. The material’s low weight helps reduce fuel consumption.

Properties  flexible shape // low weight // weather-resistant // heat-resistant // low transport volumes Sustainability aspects  easy to assemble // low weight reduces energy consumption // efficient material use

Technical textiles

GINA vehicle concept with flexible body work (Source: BMW)

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Textile architecture “Past, Present and Future” is the title of the film that brings visitors to Zaha Hadid’s new pavilion in Chicago up to date with the city’s development. The mussel-shaped building was opened to mark the 100th anniversary of the Burnham Plan. Whereas in the early twentieth century, townplanner Daniel Burnham primarily associated stone buildings with his vision of Chicago’s future urban development, the pavilion seems to offer a fresh perspective on the future: it consists of an aluminum tube construction, over which a flexible textile outer skin has been stretched. The material reacts directly to the forces acting on it, enabling new shapes that are not arbitrary. Furthermore the material, which is actually white, serves for video projections in the interior.

Burnham Pavilion in Chicago (Source: Zaha Hadid)

Textiles with a dual-wall structure are known as spacer textiles, spacers or 3D textiles and are produced using fabrics, knitted fabrics and fleeces. The space between the walls ranges from just a few millimeters to 10 cm and can be used for a variety of applications. A temperature-regulating microclimate can be created in the cavity section.

Textile space travel The small packing volume and low transport weight relative to their size when installed make compound membranes an obvious choice for use in space. On behalf of EADS, designers headed by Axel Thallemer are currently developing the Lunar Greenhouse, a folding greenhouse for use in a space station. It is intended to ensure the provision of fresh vegetables during longer stays in space, and the concept is even being advanced for use on the moon. In this case the greenhouses would be larger, and the textile membrane that facilitates the exchange of oxygen and carbon dioxide be supplemented by a multi-layered compound membrane with carbon fiber reinforcement on the exterior surface. The latter serves as protection from cosmic radiation while the steady interior temperature is assured by a noble gas filling.

Technical textiles in a space station (Source: Thallemer/Diensthuber SCIONIC I.D.E.A.L for EADS, background NASA)

Properties  dual-wall structure // low weight // high stability // temperatureregulating microclimate // heat insulation potential Sustainability aspects  low weight saves energy // heat insulation potential // efficient use of materials

Spacer textiles aerofabríx™ used in heat-insulated tents (Source: aeroíx)

116 Lightweight construction and insulation materials

Spacer textiles for hot air balloons (Source: aeroíx)

construction of hot air balloons. By filling the intermediary space with different materials, spacer fabrics can also be designed for diverse uses. If combined with embedded silicon cushions, which abruptly harden on impact, the pressure resilience for special applications and in vehicle shock absorbers can be increased many times over. They can be soaked in resin or deployed in conjunction with concrete to produce extremely light but very stable panels. products

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aerofabríx™ with flock coating (Source: aeroíx)

aerofabríx Whereas fiber-reinforced plastics have only just found their way into commercial aviation, coated fabrics and laminates are being put to ever more demanding use in paragliders, kites and balloons. For balloons, aeroíx developed a new system of insulation with the lowest density achieved worldwide. Aerofabríx is an ultra-light multi-layered fabric. The air gap needed for heat insulation is created by loosened filament fibers. During balloon flights the integrated flock insulation can save over 50% fuel. The material is also used in temporary architecture, marquees and outdoor gear.

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Parabeam ® spacer fabric (Source: Parabeam ®)

Material concept and properties

The air cavity provided between the walls makes spacer textiles extremely lightweight yet highly robust. Their particular pressure-resilient properties make them ideally suited for use in upholstered furniture and mattresses. The dual-wall structure ensures good ventilation and supports the transport of moisture and body odors. At the same time, the elastic structure has a heat-insulating effect and is eminently adaptable, making spacers particularly suitable for functional clothing such as motorcycle suits. Use and processing

In addition to being suitable for furniture and clothing, spacer textiles can potentially also be used in the construction and transport of temporary architectural structures. For tents and domes, the gap they boast can function as heat insulation, making them of interest for the

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3mesh Spacer knitted fabrics with an air-filled internal gap of between 1–20 mm ensure a high degree of air circulation in upholstered furniture, shoes, mattresses and car seats. The toughness and surface structure of the covering layers can be adapted for the particular task at hand. 3D textiles can also be used as reinforcement in dual-wall lightweight construction panels with thin walls but high rigidity (textile concrete).

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Parabeam  3D Glass Fabrics This moldable spacer fabric consists of two woven top layers, linked together by bridging threads. Impregnating the fabric with resin causes the bridging threads to stand up rigid. After hardening a rigid, low-weight composite structure emerges for use in vehicle and boat construction.

Lounge landscape made from 3D polyester spacer knitted fabric (Source: HfG Offenbach)

Where roof and hall constructions are considered, textile materials, given their low weight, have partially replaced traditional construction materials such as concrete and glass in a number of recent edifices. The most impressive examples are the new football arena in Munich, for whose facade 3,000 polymer cushions were combined in a woven honeycomb structure, and the Olympic swimming stadium in Beijing, the outer surfaces of which are covered by a soap bubble-like membrane. Material concept and properties

As a rule, textile membranes consist of highstrength, weather-resistant fluoropolymer or coated polyester fabrics. Glass fabrics with PTFE or silicon coating are also conceivable. Fluoropolymers such as ETFE or PTFE exhibit greater resistance to chemical and biological influences than any other synthetic fibers and are suitable for extreme usage across a broad range of temperatures. Coated polyester fabrics are extremely tearresistant and have a dirt-repellent protective coat made of acrylic or PVDF. ETFE films are used in the construction of membranes with thicknesses of 0.05–0.25 mm, and are harnessed in double or multi-layered air cushions. Their translucence is around 90–95 T (including UV radiation) and can be varied by printing.

117 Lightweight construction and insulation materials

Properties  ETFE film // thicknesses: 0.050.25 mm // fire behavior: B1 // tear resistance: > 300 N/mm² // weight: 250 g/m² transparency: 90-95 % (thickness: 0.2 mm) Sustainability aspects  use of daylight for interior areas // lightweight construction with efficient use of materials // long lifecycle // recyclable

Membrane textiles

Use and processing

Polyester and glass fabrics coated on both sides are used in the most diverse applications in facade, roof, and tent construction, with typical uses to date being translucent roofs over large halls or temporary exhibition structures. PTFE-coated glass fabric is used whenever a self-cleansing effect and long maintenance cycles are desired, or a non-combustible material is required. Composite materials made of PVC-coated polyester fabric or PTFE glass have gained acceptance in textile architecture. Whereas PTFE-coated glass fabrics have a life span of over 25 years, in the case of coated polyester fabrics the figure tends to be 10 to 15 years. Given the low weight of the ETFE cushions, extremely filigree load-bearing structures that are particularly light can be realized. The cushions are stretched over an aluminum frame to create large roofs and facades underpinned by the wood, steel or aluminum load-bearing structure. Without supporting structures, polymer cushions can reach spans of up to 4.5 meters.

Floating swimming pool made from a dual-wall PVC membrane (Source: Badeschiff Berlin)

Indoor swim ming pool with outdoor grounds, water park and spa facilities, as well as a sports center in Neydens, France. The building sheath was realized using transparent ETFE cushions on a wooden space frame. (Source: seele holding GmbH; photo: Matthias Reithmeier)

Use of polymer cushions in the “Bird’s Nest” National Stadium in Beijing. As horizontal protection against the weather, the open lattice structure was given a transparent membrane made from a singlelayer ETFE film, with a thickness of 250 micro-meters. (Source: seele holding GmbH; photo: Matthias Reithmeier)

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Seele Cover  Fluoropolymer fabrics made of various materials are available for membrane architecture and lightweight shell structures. These are: PTFE polytetrafluorothylene, ETFE (ethylene tetrafluoroethylene), TFA/PFA (tetrafluoroethylene perfluoralkyle vinyl lather), FEP (tetrafluoroethylene–hexafluoropropylene) and PVDF (polyvinylidenfluoride).

118 Lightweight construction and insulation materials

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CenoTec  Membranes made of polyester and glass fabrics as well as ETFE films come in a broad range of versions and formats. As in most cases the systems need to be designed for the relevant task, close collaboration with the producer is advisable. During planning and implementation, the guidelines applicable in the relevant county and load-bearing standards must be taken into consideration.

Castle courtyard roof in Dresden with a pneumatic ETFE construction (Source: CenoTec, Sattler)

Coated fabric roof over Andreasried bicycle racetrack in Erfurt (Source: CenoTec, Sattler)

Fibrous materials that are a few nanometers in size or are optimized in terms of their functional properties by nano-structured coatings or particles, i.e., are dirt-repellent, abrasion-proof, or anti-bacterial, are referred to as nanotextiles. The industrial use of nano­ fibers is still in its infancy.

Properties  quality optimization through nanocoating // exact customization to the task at hand // lightweight construction potential Sustainability aspects energy-saving through low weight // optimal use of materials

Nanotextiles Electrospinning process (Source: EMPA)

Polymer solution Capillary nozzle Fiber forming High tension

Fiber mat Counter electrode

Material concept and properties

To date nanofibers made of plastic (PA, PP, PET), biopolymers, metals, ceramics, glass and woolen proteins in combination with polymer materials have been successfully produced by opting for an electrospinning process. A high-voltage (30 kV) electrostatic field is created between the spinneret and a counter electrode. The material to be spun is subsequently compressed by the spinneret. Extremely thin, long fibers just a few nanometers in diameter then form in the electric field. The appropriate choice of material and suitable parameter settings can produce fiber material exactly adapted to the task at hand.

use

The construction industry, environmental technology, the automotive industry, and medical technology are seen as potential areas where nanofibers could be used. Nanofibers are suitable for the production of special filters, for wound dressings, for combating viral infections, and for growing human tissue for the treatment of burns. Other uses include lightweight structures in the vehicle and aviation industries such as the VW Nanospyder. In pest control, pheromones from insect pests in biopolymer nanofibers are applied to plants by electrospinning.

Nanotextile finishes

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NanoSphere  This finishing technology causes dirt and water to drip off textile surfaces. The impregnation is based on nanostructuring that functions in a similar way to a lotus flower’s self-cleansing process. The dirt-repellent property remains effective even with regular use and after several washes, and has no effect on comfort or elasticity

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3XDRY  3XDRY  combines two types of finish in one product. On the outside, it has a hydrophobic (water-repellent) effect while, on the interior, the textile has hydrophilic (water-absorbent) qualities. While the material swiftly absorbs sweat on the inside and quickly transports it away from the body, the exterior guarantees weather-resistant protection against dirt and moisture. The finish has a cooling effect.

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Nano-X  This finish inhibits bacterial growth on textiles and protects them from mechanical abrasion. Thanks to its hydrophobic properties it can be used in filters, marquees and awnings, as well as in medical garments. The fiber material has a virtually invisible coating of inorganic-organic hybrid materials that do not alter the original visual and tactile properties. Nanocyclodextrins As a finish, nanocyclodextrins can help to disperse unpleasant odors. In dimensions of just a few nanometers the coating can be used as a carrier for scents. The finish suppresses the growth of bacteria and counters mechanical abrasion.

Hydrophobic, bacteria-inhibiting textile finish (Source: Nano-X ®)

Lightweight construction and insulation materials

These nanofibers are between 250-300 nanometers in diameter and are 1,000 times finer than a human hair. They can be used to give plastics particular properties, for example UV protection. (Source: BASF press photo)

Nanotextiles Project

“Ever scarcer material and energy resources and increasing global warming are forcing authorities to impose strict conditions on the automotive industry. It is planned that cars in the future will be 100% recyclable after a minimum life Nanospyder - VW design study cycle of five years. The Volkswagen Group for the 2006 LA Design Challenge (Source: VW Design is responding to stricter legal regulations Center California; design: Patrick Faulwetter, Daniel by establishing a new production process. Simon, Ian Hunter) In order to ensure the company’s longterm competitiveness, billions of tiny nanodevices (measuring no more than half a millimeter in diameter) are being used, which are capable of assembling and disassembling the lightweight structure of a new automobile, the Nanospyder. Nanospyder - production through billions of small nano­ devices (Source: VW Design Center Thanks to the additive, highly flexible California; design: Patrick Faulwetter, Daniel Simon, manufacturing process, the Nanospyder Ian Hunter) is optimized in terms of weight, performance and energy consumption. Intelligent crumple zones adapt to external forces in advance, thereby guaranteeing high safety levels.” The Nanospyder was the VW Design Center’s entry in the 2006 LA Design Challenge. The brief was to develop concepts for especially environmentally friendly, recyclable vehicles. The Nanospyder was based on a real technological development in the Czech textile industry and demonstrated the potential inherent in contemporary nano-research. In late 2004, scientists at Liberec Technical University registered a patent for a technology comprising the weaving of fibers on a nanoscale.

Carbon nanotubes are one of the prime examples of nanotechnology. Like diamonds they consist of carbon and, given their high degree of stability and low weight are used in particular in lightweight construction and heavy-duty plastics.

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Properties  density: 1.33-1.4 g/cm³ // diameter: 0.6-1.8 nm // tensile strength: 45 billion Pa // thermal conductivity: 6,000 W/mK with RT // stable up to 1,000°C Sustainability aspects  considerable potential in lightweight construction // reduction of material used for heavy-duty plastic parts // decrease in fuel consumption in vehicle manufacturing

Material concept and properties

In terms of structure, CNTs consist of furled layers of graphite with a particularly stable hexagonal honeycomb configuration. They can be used for heavy-duty mechanical purposes, being five times as rigid as steel, and boast a strength that is twice that of diamonds. At the same time carbon nanotubes have a density of only 1.4 g/cm3 (steel 7.8 g/cm3). While the calculated tear resistance exceeds that of steel by over 135 times, the level of electrical conductivity is comparable with that of copper. Compared with copper wire, however, their level of thermal conductivity is exceeded over 1,000-fold.

Carbon nanotubes (CNT) ®

Whether carbon nanotubes represent a danger or health hazard has yet to be established. Studies on mice in 2009 imply that CNTs can accumulate in the pleura and cause damage to the tissue similar to that caused by asbestos and cancer. Use and processing

Carbon nanotubes are currently used as an additive in heavy-duty polymer materials for dynamic applications or for lightweight construction purposes. Examples are sports equipment such as tennis and baseball bats, ski sticks and surfboards. There is repeated discussion with regard to their use in rotor blades for wind energy generators. Incorporated in construction materials and concrete, CNTs could deliver a significant improvement in rigidity, thereby considerably reducing the amount of material used. In the automotive and aviation industries, their inclusion could help considerably reduce fuel consumption. The material’s high level of thermal conductivity could enable the casing of electrical devices for outdoor use to be heated. Their anti-static effects could also be put to use for the packaging of electronic component parts. Coatings with CNT particles can be chemically vaporized (CVD process).

CNT as an additive is used in heavy-duty polymer materials (Source: Bayer MaterialScience)

Baytubes ® integrated in a baseball bat to improve hitting power (Source: Bayer MaterialScience)

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Frontier Carbon Corporation CNTs were discovered by NEC in 2001, since when work on a large-scale manufacturing process has been on-going in Japan. The first production plant opened in 2001. The aim is to manufacture hi-tech products based on carbon nanotubes and the necessary components.

CNT integrated in boat lacquer to reduce resistance to current (Source: Bayer MaterialScience)

Baytubes  At Bayer MaterialScience in Leverkusen, production of carbon nanotubes began in 2005. With a new production process for multi-wall carbon nanotubes (MWNT) the company intends to become one of the world’s largest manufacturers worldwide. They are used in composites such as, primarily, plastic transport containers, ice hockey sticks and power boats. Incorporating carbon nanotubes in the lacquer for ships’ hulls minimizes resistance to the current and considerably reduces fuel consumption.

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FIBRIL Hyperion Catalysis International in Cambridge (USA) is another important producer of carbon nanotubes. Multi-wall nanotubes are also produced here, which the company uses for the electrostatic discharging of electrical parts.

Structure of a carbon nanotube

Whereas in fiber and particle-reinforced plastics, improvement to the characteristics and increased strength are achieved by embedding fibers or particles from a material other than that used for the matrix, improvements to the quality of self-reinforced thermoplastics tend to be achieved by aligning the molecular structure in semi-crystalline areas in the plastic structure. Material concept and properties

The characteristics of self-reinforcing thermoplastics are comparable with those of fiberglassreinforced plastics. Strength and rigidity levels are several times higher than those of conventional thermoplastics. Self-reinforced thermoplastics also have greater impact strength, are more stable when exposed to high temperatures, and more wear-resistant. Expansion caused by heat is only half as much. One advantage is the possibility of pure recycling. Furthermore, self-reinforcing thermoplastics weigh less than fiberglass-reinforced plastics. Use and processing

As a result of new legal stipulations on the recycling of scrap cars and given the opportunities they offer for pure recycling, self-reinforced thermoplastics have enormous potential in vehicle manufacturing as a substitute for fiberglassreinforced parts such as bumpers, door lining, and luggage racks. Suitcases, protective sports gear, loudspeakers, surfboards and kiteboards are all well-known lightweight products made of the material. Self-reinforced thermoplastics are normally processed in molding presses. Unlike normal thermoplastics, on account of the orientation of the fabric strips, self-reinforced varieties still boast a relatively high degree of stability after exposure to heat, necessitating re-shaping by punching. For this reason vacuum shaping is not possible.

121 Lightweight construction and insulation materials

Properties  mechanical qualities comparable with those of fiberglass-reinforced plastics // pure // stable when exposed to heat // wear-resistant // low density Sustainability aspects  lower in weight than fiberglass-reinforced plastics // pure recycling

Self-reinforced thermoplastics Products

®

CurV  The company Propex manufactures the first selfreinforced thermoplastic worldwide, made from 100% polypropylenes. The matrix is produced by deliberately melting the surface structure of the thermoplastic fabric web structure in a molding press. Its appearance is reminiscent of carbon fibers. The material does not split and is highly abrasion-resistant.

®

Pure  This self-reinforced plastic – composed to 100% of polypropylenes – is available in the form of boards, panels and fibrous material. Waste that occurs during processing is just as much recyclable as building parts at the end of their life cycle. Pure® fibers were optimized for thermoforming purposes. Given its high rigidity and break-proof qualities it is suitable as a lightweight

Suitcase made of self-reinforced polypropylene (Source: Propex)

construction material for use in sport and vehicle manufacturing. The material can be produced with UV-proof properties. For architectural applications, sandwich panels are available with Pure® as a cover layer and PU-foam or honeycomb structures in the middle.

122 Shape-changing materials

Shape Memory Alloys (SMAs)…126 Formgedächtnislegierungen (FGL)…126 —— Shape Formgedächtniskunststoffe Memory Plastics (SMPs)…127 (SMP)…127 — Thermo-Bimet— Thermobi­ metalle…128 — Piezoelektrische Keramiken als…128 — Piezoelectric Ceramics (PECs)…128 (PEK)…128 — Plastics Piezoelektrische — Piezoelectric (PEPs)…129Kunststoffe — Electro(PEP)…129 active Polymers…130 — Elektroaktive — Buckypaper…131 Polymere (EAP)…130 — — Bucky Paper…131 — Hydrogel…132 Hydrogel…132

— 05 —

123 Shape-changing materials

124 Shape-changing materials

The use of materials that change shape on their own is relatively new in architecture and design. To date, few creative minds have actually risked corresponding designs, although the effects that can be achieved are nothing if not remarkable. Yvonne Chan Vili was one of the first to research the use of textiles incorporating woven wires made of shape memory alloys (SMAs) for partitions and wall hangings. SMA materials store shape information in their molecular structure. At low temperatures they can be reshaped, and reassume their original shape when exposed to heat. When exposed to strong sun SMA textiles can be used to automatically darken a room. SMA plastic foams in carpeting or the use of thermo-bimetal strips in lamps are now not unknown. The further potential of shape-changing materials is making them interesting for future use, particularly for industrial designers. One idea, for example, is to lay piezo-materials under pavements or to integrate them in the soles of shoes, in order to use the vibration in a step to generate electricity. Work is currently being conducted on applications for electroactive polymers for use in aviation and vehicle manufacturing. One current line of investigation is car seats, to enable these to fully adapt to the relevant human body at all times. Hydrogels, which expand under the influence of water while at the same time remaining dry on the surface, are used in particular in hygiene products such as diapers. The future will reveal whether beneficial product design concepts that go beyond current use in model making can be found.

125 Shape-changing materials

Hood with in-sew n shape memory alloys. This garment by the designer Max Schäth imitates man’s senses and feelings in abstract form. (Source: UdK Berlin; photo: Özgür Albayrak)

In recent times, the use of yarns made from shape memory alloys in textiles for fashion design and interior architecture has resulted in interest in one of the most unusual material classes there is. At low temperatures they can be brought out of shape. Having been heated to above the structure’s transformation temperature, the material remembers and reassumes its original shape. Shape memory alloys are also referred to as “memory metals”. Material concept and properties

Shape memory alloys store shape information in their molecular structure. A distinction is made between three types of memory effects. The oneway memory effect refers to alloys capable of returning to their original shape once after having been heated. When it has cooled again, the material retains its shape. By way of contrast, the two-way memory effect describes the possibility of multi-shape return after the material has cooled down. Some shape-memory alloys boast special elastic properties up to twenty times higher than normal materials at a constant temperature. This quality is referred to as super-elasticity or mechanical memory effect.

126 Shape-changing materials

Sustainability aspects  control function without electronic components // reduced construction work

Shape memory alloys (SMAs)

Use and processing

Memory metals are used in particular whenever movement is to be made possible in a limited amount of space. One such example is the controlled approach needed when unfurling solar sails in space travel. Given the sound biocompatibility of many shape memory alloys, they are of interest for use in medical technology. In 2006, one of the Fraunhofer prizes was awarded for the development of a heart valve, made of a material with shape-memory properties, which is guided in compressed form through an artery to the heart by means of a catheter, without any need for open heart surgery. The temperature of the blood suffices to trigger the shape-memory effect and enable the ninitol stent and thus the heart valve incorporated in it, to unfold and assume their effective shape. Memory metals in the form of wire and yarn are easy to process. For this reason they are of interest also in interior design and are used as interwoven threads in textiles employed to darken a space or shield it from sight. The Italian clothing company Corpo nove attracted attention with a shirt made of shape memory fibers (nitinol-coated nylon). Memory metals are also already being used in load-bearing structures in architecture.

Properties  nickel-titanium alloys // high elasticity (10 times greater than that of steel) // good biocompatibility // high buckling strength

Products

CoreValve ® system - artificial heart valve with nitinol-based memory effect (Source: Medtronic)

When cold shape memory wire can be bent and returns to its original shape when heated to around 90°C. (Source: Lekkerwerken)

Shape memory alloys are available in the form of sheets, strips, springs, clasps and wire material. Alloys made of nickel and titanium (Ni, Ti) in particular are used for shape memory alloys and are also known as nitinol, Memry, tini-alloy or Livewire. Compared with other available products, they have the greatest market presence. As a general rule, the temperature range in which memory metals play out their specific property profile is –35 to +90°C. They can in some cases transfer large forces in several cycles of 100,000 movements without fatigue. Nickel-titanium alloys boast good tensile strength and have better ductile fracture properties than alternative memory metals. In addition, they are biocompatible and extremely corrosion-resistant. Further shape memory alloys consist of copper-zinc (CuZn), copper-zinc-aluminum (CuZnAl), copper-zincnickel (CuZnNi), iron-platinum (FePt) and gold cadmium (AuCd).

For years, intensive research work was conducted on how to transfer the shape memory effect to plastics. The first applications are now available on the market. The best examples are mattresses made from visco-elastic foam (memory foam) which, when exposed to heat, adapt to the shape of the human body, and plastics with nanoparticles, which change shape in a magnetic field.

127

Positive aspects  ergonomic qualities of memory foam // avoidance of medical operative intervention

Shape-changing materials

Material concept and properties

Having had their geometry changed, shape memory plastics are capable of reassuming their original state. External influences such as heat, light or a magnetic field trigger this memory. In the case of photosensitive memory polymers (e.g., butyl acrylate) a change in shape can be set to a particular wavelength. The original shape can then be reproduced through illumination at another wavelength. Incorporating finely spread magnetic nanoparticles made of iron oxides in the plastic can successfully trigger a change in shape in a magnetic field. The field’s energy is transformed into heat.

Shape memory plastics (SMPs)

use

Potential for the use of memory foam can be seen in all fields in which the human body requires supporting or cushioning functions from flexible materials. Examples include pillows, mattresses and carpets. Shape memory plastics were developed primarily for medical purposes wherever metallic shape memory alloys cannot be used on account of the side effects they produce (e.g., suture materials). Catheters made of memory polymers could be operated by remote control in a magnetic field.

Products

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Pure Moss  Visco-elastic carpets are based on a multi-layered structure made of PUR-foam material and bielastic knitted fabric, which was developed by Bayer MaterialScience and is marketed by kymo GmbH. Given its low-impact properties it is suitable for homes and public areas, as well as for sports facilities and physiotherapy.

™

Veritex This resin has a special shape memory. If the plastic is heated to a temperature that is higher than its melting point it changes from a rigid to a flexible state and can be reshaped and stretched to double its original length. When it cools down the shape it has assumed sets. When reheated the material returns to its original shape. The process can be repeated ad infinitum. Fitted with thermochromic pigments, the activation temperature can be discerned exactly by the change in color. As a rule Veritex™ is sold as panel material with a high degree of rigidity.

™

Essemplex This shape memory polymer is available in granulate form and can be processed by injection molding, extrusion, or thermo-forming. The material always remembers its original shape. There are two versions available, in which the memory effect is activated at either 34°C or 43°C. The memory process can be repeated without any loss of quality.

Pellets made of the shape memory poly mer Essemplex (Source: CRG industries)

Carpet made of shape-memory foam material (Source: ky mo)

It looks like a closed poppy bud and indeed, is named accordingly. Some ten seconds after it has been switched on it slowly begins to open. The effect is triggered by the use of thermo-bimetals for the delicate leaves, which open out in a pre-determined direction when exposed to heat.

128

Properties  changes shape as a result of differing thermal expansion coefficients Sustainability aspects  no need for elaborate mechanisms in controls and switches // automatic switch-off function

Shape-changing materials

Thermo-bimetals Material concept and properties

Bimetal lamp “Poppy” (Source: serien.lighting)

Over the past few years, piezoelectric materials have gained in importance in several fields of application. Although the piezo effect, which refers to the creation of an electrical field in response to a change in shape of certain material surfaces, has been known since 1880, it is only since new legislation and environmental stipulations have been in place that demand for materials with piezoelectric qualities has increased. Material concept and properties

The piezo effect can be traced back to the brothers Jacques and Pierre Curie. They discovered that in response to the deformation of the surfaces of certain materials, electrical charges are generated and an electrical field created. They proved the effect of tourmaline and quartz crystals and were able also to reverse it. In other words, after applying electrical current to piezo crystals,

Thermo-bimetals are composite materials made of two sheet metal strips that are rolled and firmly connected to one another. As the two metallic strips have different thermal expansion coefficients, when they are heated their different degrees of expansion cause a bending effect. This reveals the side of the material with the lower thermal expansion (passive components). While the active component is largely composed of ironnickel-manganese or manganese-nickel-copper alloys, iron-nickel (invar) and nickel-cobalt-iron (super invar) alloys can be used for the passive

components. In Europe the specifications supplied with regard to bimetals refer to the composition of the active components, and in America to the passive components. Use

Bimetals are used in measuring instruments, for example for metallic spirals in thermometers, and serve as controls and switches for contacts that switch off automatically. They are used in irons, kettles, and coffee machines. A bimetal strip positioned near a filament and integrated in the flow of current in a bulb can cause continual flashing.

Properties  electric charge in response to change in shape // up to a temperature of 250°C // possible with lead-zirconatetitanate (LZT) Sustainability aspects  potential for the generation of energy from alternative sources // control without elaborate mechanisms

Piezoelectric ceramics (PECs)

129

deformation and oscillations can be detected. In relation to the levels of the piezoelectric component, the amplitude is on a scale of one in a 1,000. Lead-zirconate-titanate (LZT) is used frequently. This ceramic structure demonstrates piezoelectric properties up to a temperature of 250°C.

Shape-changing materials

use Structure of flexible piezo material

Nowadays, piezoelectric ceramics are used in vehicle manufacturing, in particular for fuel injection pumps, to cushion vibration, and for parking assistance systems. Other examples of typical uses include loudspeakers, microphones, quartz watches, and sonar systems in submarines. In industry they are used in particular for pressure sensors. Laying piezo-elements beneath pavements and roads and using the vibrations generated by pedestrians and passing cars to create electricity is a visionary idea. Piezo-elements could also be inserted in the soles of shoes to produce energy for outdoor applications. In architecture, consideration is being given to generating electricity from the oscillations to which a building is exposed through the weather.

Piezo-electronic polymers are plastics with special properties that can be used in architecture to prove a person’s entry into a room.

PZT

PDMS

MgO

“Grow” project - a curtain with leaf-like solar panels with a piezo generator in the base, which transforms wind-induced movement into energy (Source: Samuel Cabot Cochran)

Power Leap - floor system with piezoelectric properties for the transformation of kinetic energy into electrical energy (Source: Elizabeth Redmond)

Properties  electrical charge following deformation // possible with PVDF, PP or PE Sustainability aspects  reduction in the amount of control technology

Piezoelectric plastics (PEPs) Loudspeaker made of a piezoelectric PVDF film (Source: Erfinderladen, Berlin)

130

Material concept and properties

Proof of the piezo effect on a polymer material was first established in 1969. Polyvinylidene fluoride (PVDF) is a typical example. Following mechano-electric treatment involving elongation and subsequent polarization in an electrical direct current field, it acquires piezoelectric properties. Polyolefins such as PP and PE can also be transferred to PEP materials. use and processing

Force, pressure and ultrasonic sensors for controlling positioning systems, servo systems, and injection ducts are typical uses for piezoelectric polymers. They are the fundamental elements in

Shape-changing materials

surveillance technology, medical diagnostics and non-destructive material testing. Piezoelectric polymer films are also used as large sensors and flat loudspeakers. In architecture they are laid under floors to monitor people’s routes. Piezopolymers can be processed using the usual plastic processing techniques, though one must contend with limited formability.

Polymers or composite materials made from plastics, which change their volume (that is, contract or extend) when subjected to an electrical charge, are referred to as electroactive plastics. In development laboratories work is currently being conducted, for example, on the vision for an artificial muscle. Using morphing materials, researchers at NASA aim to change the shape and properties of an aircraft. In the process they are pursuing various approaches, whose structure and way of functioning differ substantially from one another. Soft dielectric elastomers (DEs) and ionic polymer metal compounds (IPMC), for examples, are solutions that are in widespread use.

Properties  change in volume following subjection to an electric current Sustainability aspects  no need for elaborate mechanism in car seats // energy-saving potential through adapting the shape of a vehicle or aircraft to the ideal flow geo­ metry // tidal power stations possible

Electroactive polymers

Material concept and properties

Soft dielectric elastomers (DEs) consist of elastic plastic films (based for the most part on acrylic or silicon), which are coated on both sides with conductive graphite. When an electrical charge is applied electrostatic pressure is generated between the thin films, which condenses the thickness of the polymer film. This causes the DE to expand sideways. Depending on the shape, DEs are used to produce actuators that can expand, bend, and contract. As electrical energy is transformed into mechanical energy, the degree of efficiency is virtually 70%. Ionic polymer metal composites (IPMC) consist of ionomers such as sulphonate and carboxylate, which are coated with electrodes made of highly conductive metals. When low-voltage electrical current (2–3 watts) is applied, ion migration occurs and the material consequently curves like a bent beam.

Structure of a dielectric elastomer

Compliant Electrodes

Accumulation of Charge

Fläche, Area, A A

E=V/t

Thickness, t High Voltage

z x

Dielectric y

Planar Expansion

131

use and processing

In the past, electroactive materials served the production of loudspeakers. Nowadays thought is being given to using electroactive silicon films to cushion vibration in aircraft casing and in vehicle flooring. Other ideas involve using EAPs as windscreen wiper blades or as elastic tubes with variable diameters. In the future, electroactive materials are intended to be controlled over a wide area and enable changes to be made to the shape of a wing during a maneuver to make the aircraft more energy-efficient with regard to the relevant stage of the flight. NASA is currently conducting research in this field. In 2007, scientists at ETH succeeded in getting an airship driven by a large artificial muscle made of EAP (EP), to glide through the air like a fish. Energy sourcing is another field in which electroactive plastics could be used in the future. Energy from the wind and sea currents can be transformed into electrical energy using EAP films. Furthermore, artificial muscles in prosthetic limbs are intended to enhance the mobility of physically challenged people. With an intelligent design, electroactive polymers can be adapted to the human body. Use in car seats generates enormous potential that could fundamentally change our previous idea of mobility.

Buckypaper is one of nanotechnology’s prime products. It consists of a tangled aggregate of carbon nanotubes (CNT), which can be reshaped following subjection to an electrical current.

Shape-changing materials

EAP as a large muscle for an airship (Source: EMPA)

Structure of an ionic polymer metal composite Electrodes

-

Electrodes

+

-

ON

OFF

Poly mers

Poly mers

Properties  tangled aggregate of carbon nanotubes // can be reshaped following subjection to an electrical current // heat production Sustainability aspects  no need for elaborate mechanisms // material-efficient thermal elements

Material concept and properties

Their hexagonal honeycomb structure makes carbon nanotubes a high-strength fiber material. They are twice as hard as diamonds and, with a density of just 1.4 g/cm3 they are substantially more stable than all previously known construction materials (see CNT). Having subjected a strip of paper made of CNT to an electrical current, scientists at the Fraunhofer Institute were able to change its shape in an electrolyte bath and on a CNT polymer composite. For this reason Buckypaper is being tested in its function as an actuator. A further property is the generation of thermal energy, making buckypaper suitable for use as a heating element.

++

Buckypaper

−

+

Shape-changing materials

Cl‾

Shape changing can be used, for example, to control miniature robots and in micro system technology. Optical systems also provide potential uses for Buckypaper. Micro-invasive surgery in particular offers countless opportunities. Given its homogenous distribution of heat, Buckypaper is ideally suited to heat seats, under-floor heating, de-icing systems and instantaneous heaters. With a composite system designed by the Fraunhofer Technology Development Group (TEG), temperatures of around 60°C can be achieved.

132

Expansion of Buckypaper in an electrolyte bath

Na+

use and processing

Buckypaper made of aggregated carbon nanotubes (Source: Fraunhofer Institute for Manufacturing Engineering and Automation)

Children love it – the slimy mass that wobbles in a variety of different colors: jelly. It is the best-known example of a hydrogel. Contrary to what one might expect, gelatin only accounts for around 3% of the total volume, the rest being aromatized and colored water.

Properties  water storage // dry surface // enormous volume expansion Sustainability aspects  potentially no need for elaborate control engineering in actuators // reduced cost of model con­ struction

Material concept and properties

Hydrogels are composed of a firm jellying and thickening agent, and water. It is basically a 3D insoluble network of polymer chains, which, when water is added, swells up and increases

Hydrogel enormously in volume. The material properties are determined by the interaction between the network and liquid phases, though the surface remains dry. The forces generated during the material’s expansion can be used in technical contexts. Super absorbers are a special group of hydrogels, as when water is added the volume of the polymer network expands to a disproportionate extent. Polyacrylic acid gels, for example, can absorb 1,000 g of water for every gram of polymer. use

Disproportionate expansion of a super absorber when water is added (Source: Geohumus)

Given their volume-changing qualities, hydrogels come into question in particular as sensors, actuators in micro-systems, and in control engineering. Their biocompatible and fabric-like properties are used for implants and soft contact lenses. Furthermore, hydrogels help healing processes and the self-cleansing of chronic wounds. The relevant areas of the skin are constantly

Hydrospan - a possible use in model construction (Source: Industrial Polymers Inc.)

supplied with moisture, helping dead tissue to be discharged. In model construction, hydrogels are used to create models of objects that need to be enlarged.

133 Advertisements Shape-changing materials

The EcoCommercial Building Program…134 — Barktex…136 — Conbam…137 — hollomet…137 — Nolte AirMaxx…138 — formvielfalt…138

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The EcoCommercial Building Program

Sustainable Construction Pays Off

A GLOBAL COMPETENCE NETWORK FOR SUSTAINABLE CONSTRUCTION

Sustainable Bayer administration building in Diegem, Belgium - 40% less energy consumption compared to standard office buildings today - CO ² emissions reduction by 300 metric tons per year through polyurethane insulation - Healthy indoor environment due to water based polyurethane floor coatings - Energy efficient and highly durable media facade using Makrolon ® clad LEDs - Shatterproof transparent interior decoration elements made of Makrolon ® - Winner of the “European GreenBuilding Award” in 2010 and the “Belgian Prize for Architecture and Energy” 2009

Architects, project developers, construction firms, and corporate real-estate managers have one thing in common: They require innovative material and service solutions that enhance energy efficiency and reduce buildings’ ecological footprint. In this way, operating costs can be minimized and valuable resources saved in the long term.   Bayer MaterialScience’s EcoCommercial Building Program offers construction industry decisionmakers an integrated concept for energy and cost efficient construction for the first time. With its global interdisciplinary network of members, the EcoCommercial Building Program provides targeted support for the implementation of public and commercial buildings in many regions of the world. Only the highest energy efficiency standards are taken as a benchmark, enabling significant savings through to zero emissions buildings. The EcoCommercial Building Program pools the expert knowledge and competence of Bayer MaterialScience and that of the individual network members, giving you access to a network of proven experts in the field of sustainable buildings, which is unparalleled in the market.

INDIVIDUAL ALL-ROUND SOLUTIONS AND LOCAL KNOW-HOW

The EcoCommercial Building Program is a member of:

Be it solar elements integrated into the roof, solar thermal systems for water heating, intelligent use of daylight, an external facade illuminated by LEDs, polyurethane insulation, polycarbonate glazing, or services ranging from initial analysis to the creation of comprehensive energy concepts in the early planning phase, through to the certification of the finished building: The members of the EcoCommercial Building Program offer the ideal solutions for your building project. Through these effectively integrated individual measures, you can achieve the best possible results with respect to both environmental protection and cost efficiency. If project planning takes into account sustainable aspects from the outset, then marginal investments can be minimized and pay for themselves within only a few years, thanks to the resulting lower operating costs. Reason enough to involve the EcoCommercial Building Program’s network from the word go. The concept is not tied to any specific country or region: Our regional network members worldwide optimize your building project for local climatic conditions almost anywhere on the planet. YOUR BENEFITS AT A GLANCE

Emissions neutral daycare center in Monheim, Germany - 91% primary energy savings compared with the German standard and EnEV 2009 - Emissions neutral energy balance averaged over one year - Highly efficient thermal insulation - Use of renewable energy sources – photovoltaics, geothermal and solar thermal energy - Optimal use of daylight combined with efficient lighting technology - Award winner in the “Energy-Optimized Building 2009” competition held by the German Federal Ministry of Economics and Energy

No two construction projects are alike. Each project involves different requirements. Through the EcoCommercial Building Program, we are pleased to offer you materials know-how of the highest international standard as well as an interdisciplinary network of experts to support your project from the planning stage through to completion: - Practical involvement and strategic and technical consultation from the early planning phase through to certification of the finished building - Innovative high-tech solutions - Integrated energy and materials concepts based on construction evalua- tion using dynamic simulations of the building and amortization calculations - Regional network contacts for expert implementation globally

For further information, please visit www.ecocommercialbuilding.de Lisa Ketelsen The EcoCommercial Building Program Region EMEA, Corporate Development Bayer MaterialScience AG Phone +49 (0) 214 / 3 04 80 19 Fax +49 (0) 214 / 3 02 39 31 [email protected]

Barktex

®

TEXTILES AND COMPOUND MATERIALS MADE OF TREE BARK

A Symbiosis of Innovative Material and an Ancient Tradition

Bark nonwovens are an ancient material with a history that stretches back across the millennia. Designers appreciate the unique texture, tactile properties, and highly expressive look. The bark of the Ficus natalensis is in a state of permanent growth and can be harvested once a year without the tree needing to be felled. The nonwoven made of it forms the basis for a broad range of rigid and flexible elements, e.g., semi-finished products that can be molded 3D and gained using a low-energy and in part carbon-free process. The auxiliaries used are biopolymers, natural resins, oils and waxes, and fatty acids.

 ®

The semi-finished product with the BARKTEX brand name is destined for use in various industrial and crafts sectors: interior fittings and tradefair structures, furniture, casings, unique surfaces, automotive parts.

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BARK CLOTH is the pioneer and leading innovator in systematic bark textile production. In 1999, it started work in cooperation with organic farmers in Uganda. In 2005, the UNESCO declared the crafts production process part of the World Cultural Heritage. What started as a development aid project now secures the income of hundreds of small farming families. BARK CLOTH is consistently moving the development and production of economically, ecologically and socially sustainable fiber materials forward and is a member of the Bio-Pro Baden-Württemberg biomaterials cluster.

 ®

The German-Ugandan corporate group has received several awards for the materials it has developed, such as the iF Material Design Award 2005, Materialica Design + Technology Award 2005 and 2008, “2008 BioMaterial of the Year”, as well as being nominated for the official Design Award of the Federal Republic of Germany in 2007 and 2011.

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In Uganda, BARK CLOTH operates the International Bark Fibre Research and Training Institute, which is dedicated to pooling the knowledge of bark textile production in Africa, Latin America and the South Pacific and developing additional industrial and crafts applications for bark materials.

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BARK CLOTH  _Europe Gewerbestr. 9 79285 Ebringen Germany Oliver Heintz, Mary Barongo-Heintz Phone +49 (0) 76 64 / 4 03 15 60 Fax +49 (0) 76 64 / 4 03 15 61 [email protected] www.barktex.com

Conbam

hollomet

The Bamboo Specialist

Multifunctional structures made of metal hollow spheres and sponges

Both engineers and designers are taken with bamboo materials thanks to their aesthetic qualities and material properties. It provides countless opportunities for green architecture – from the natural canes through to finished, sealed parquet flooring. Bamboo specialist CONBAM offers a great selection of bamboo canes, bamboo fencing, bamboo panels and floor coverings. Over the last ten years, CONBAM had developed extraordinary applications and realized modern buildings using sustainable bamboo. Steady growth, a range of awards, and a great response in the press all attest to the company’s success. CONBAM has, for example, won the red dot product design award and the iF material gold award.

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CONBAM  Advanced Bamboo Applications An der Vogelstange 40 52511 Geilenkirchen Germany Dipl.-Ing. Christoph Tönges Phone +49 (0) 24 51 / 4 82 45 45 Fax +49 (0) 24 51 / 4 82 45 44 [email protected] www.conbam.de

After a development leadtime of some ten years we are presenting completely new, cellular metallic and ceramic materials with surprising properties. They are attracting great interest as they enable solutions for tasks specifically relating to lightweight construction, stability, noise and heat insulation, catalytic backing materials and innovative product design. The metal hollow spheres can, for example, be made from any manner of metal powders. Thus, they can be used to make high-grade steel panels that have only 5% of the weight of a solid panel, an interesting visual structure and are self-supporting: an innovative and multitalented material.

The porosity and stability of the metal sponge (it can likewise be made from different metal powders) can be selected as required and the material gives both architects and designers great scope. Examples are air vents with filtering and noise-insulating properties, visual effects with illumination elements or the use of the sponges as dividers in rooms. In the chemical and car industries, the material is preferred for its immense inner surface and the low pressure loss if used as a medium for a catalyst. These advantages mean the material also helps lower CO2 emissions and it is also decidedly eco-friendly given its recycling basis.

hollomet GmbH Grunaer Weg 26 01277 Dresden Germany Wolfgang Hungerbach [email protected] Phone +49 (0)351 / 2 58 43 05 Fax +49 (0)351 / 2 58 45 80 26 7 [email protected] www.hollomet.com

Nolte AirMaxx

formvielfalt

AirMaxx ® Gain lightness!

FIRE THE IMAGINATION BY DESIGNING WITH INNOVATIVE MATERIALS

 ®

AirMaxx is a new light premium wooden material that is produced by inserting polystyrene balls into the middle layer. AirMaxx is about 30% lighter than conventional chipboards, meaning the materials is suitable for all applications that seek to combine modern design and lightness. AirMaxx panels can be coated and worked like any other chipboard. This is their great advantage over honeycomb panels and other light construction materials and destines them for any number of uses. You will find AirMaxx used in furniture, work tops or in shipping and caravan building.

 ®

 ®

 ®

- Weight savings of up to 30% compared to normal chipboard - Resource-sparing manufacture - Can be worked using conventional equipment and requires no additional investments - Can be coated with Melamine, foil, and coating materials - Post-forming, milling or sawing as per usual - Ideal for ready-to-go furniture and commercial and trade-fair construction

Paper honeycomb structures steeped in resin for interior applications, technical metal wovens for acoustic and architectural applications, airy foamed structures made of aluminum or extremely light hollow stainless steel spheres for pharmaceutical uses: The range of applications is immense and highlights the immense potential for the most different of materials solutions in other areas that can be brought to bear in trade-fair and exhibition design. The choice of material for your trade-fair stand is becoming increasingly important as a means of supporting your brand message. Sustainable light construction materials that are easy to re-use or recycle symbolize a responsible stand on our environment, something no modern entrepreneur should shy away from. On behalf of a global clientele, we at formvielfalt design innovative and sustainable trade-fair stands. Light construction materials from “non-related” applications create a fitting context for your trade-fair presence. We use the scope this offers to foster the brand statement made by your unique trade-fair architecture.

Nolte Holzwerkstoff GmbH & Co. KG Konrad-Nolte-Straße 40 76726 Germersheim Germany

formvielfalt GmbH Albert-Einstein-Straße 1 64823 Groß-Umstadt Germany

Bernd Einfeldt Phone +49 (0) 7274 / 9 47 0 273 Fax +49 (0) 7274 / 9 47 0 279 [email protected] www.rheinspan.de

Thea Riemann Phone +49 (0) 60 78 / 9 30 6 0
 Fax +49 (0) 60 78 / 9 30 6 78
 [email protected] www.formvielfalt.de

140 Multifunctional materials

Biomimetic Materials…144 — Color and Transparency-changing Materials…145 — Dirt-repellent Surfaces…146 — Electrorheological and Magnetorheological Fluids…147 — Phase Change Materials (PCM)…148 — Loam…150 — Moss…151 — Zeolites…152 — CO2-absorbing Materials…153 — Scent Microcapsules…154 — Nano Titanium Dioxide…154 — Nano Silicon Dioxide…155 — Nano Silver…156 — Nano Gold…157 — Nanopaper…158 — Self-healing Materials…159

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141 Multifunctional materials

142 Multifunctional materials

Surfaces for medical applications that destroy bacteria, phase-change materials that adjust to the climate, textiles that react to body heat, and glass panes that alter their transparency: in recent years it has become apparent that new products developed by scientists and manufacturers of materials, in addition to the material component in a traditional mechanical sense, also always reveal a virtual, because intelligent, reactive side. Driven forward by nanotechnologies and bionics, it is now possible to produce materials with a whole range of additional functional benefits, which are altering the former view of materiality on a long-term basis. Multifunctional materials are replacing traditional solutions that were only possible with much construction work and a lot of energy. As a result of this new group of materials, the size of air conditioning units, the constructional complexity of fitness machines and the need to install a kitchen extraction unit are set to change significantly. Initial applications, which stand out particularly on account of their low material and energy inputs, are already on the market. Nano titanium dioxides or mosses applied to surfaces help cleanse air, while other functional materials are capable of storing CO2, the key greenhouse gas, on a long-term basis. Nowadays scientists are even advancing a topic that only a few years ago would have been inconceivable: the development of self-healing materials.

143 Multifunctional materials

Concrete surface that reacts to moisture (Source: Solid Poetry ®)

Antibacterial coating for medical applications (Source: Möller Medical)

Since the 1990s, researchers worldwide in the field of bionics have been attempting to transfer biological structures to technical applications and to use them as a basis for construction materials. Whereas modern high-performance materials frequently boast one or just a few properties, most biomimetic materials exhibit multifunctional qualities. Material concepts and use

Based on: Diatom At times, diatoms are spherical with evenly distributed openings; at others, a beam-like shape determines their geometry. Nowadays, several thousand different types are known to man. What they all have in common is a lightweight but at the same time rigid shell, which protects them from predators and counters the weight of the water column. In order to be able to use the rays of light hitting the ocean’s surface for photosynthesis, the structure needs to be able to float on water. The shell, which measures a mere twentieth of a millimeter, and whose structure is of great interest for technical applications, contains pores, gills, and honeycombs. Scientists have for several years marveled at the high ratio between low weight and simultaneous great rigidity. At the Alfred Wegener Institute in Bremerhaven, for example, researchers have successfully transferred the structure on to a car wheel rim that, while highly stable, is also substantially lighter than conventional rims and is meant to deliver enhanced road grip. In another project a plaster substitute for treating broken bones is being developed. This will be considerably lighter than the previous solution and feature perforations, through which doctors can stimulate muscles and thus speed up the recovery process. Based on: Nacre Nacre is a visually very striking, extremely durable and corrosion-resistant layer on the inside of a wide range of muscles and snails. It is a composite of calcium carbonate (aragonite platelets) and a small amount of organic molecules. These are located between the mineral layers and act like a flexible cement that keeps the brittle plates of lime together. This prevents cracks forming. As yet, scientists have not succeeded in producing nacre artificially, though the layer would lend itself to a wide variety of technical applications, ranging from scratch-resistant car paints and bone substitute materials to coatings for offshore structures. Based on: Bone In particular the structure of bone, which is very hard and compact in several places, and porous and spongy in others, offers great potential for lightweight construction. Bones are particularly

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Properties  lightweight construction potential // porous material structure // extreme rigidity // corrosion-resistant Sustainability aspects lightweight construction aspects // material qualities optimized for the task at hand

Multifunctional materials

Biomimetic Materials

Despite its low weight the wheel rim, based on Arachnoidiscus, stands out for its high level of rigidity. It was developed for fiber composite materials such as CFK and GFK, just 4,000 cm³ by 17 inches. (Source: Alfred Wegener Institute for Polar and Marine Research; photo: C. Ham m)

Based on the diatom Arachnoidiscus japonicus with radial and concentric bracing. (Source: Jan Michels, Alfred Wegener Institute for Polar and Marine Research; photo: L. Friedrichs)

Antarctic diatoms (Source: Alfred Wegner Institute for Polar and Marine Research)

The special appearance of nacre (Source: University of Ulm)

light and bear up to extreme loads. The Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) developed a simulation program that calculates the internal structure and density distribution of bone material, and deduces the structure of a material for a building component. This can subsequently be produced layer by layer from metal powder using the additive technology laser sintering.

Left: the structure of a bone (Source: Fraunhofer IFAM) Right: ultra-light, permeable medical support bandage Cellfix (arm splint: 62 g; leg splint: 165 g) (Source: AWI)

Glass facades whose transparency and translucency change when the sun shines on them, wallpaper that changes color when touched by hand, and seating that makes the sitter’s behind perfectly discernible after use. In recent years materials and surface finishes that respond to influences in their surroundings and reveal a quality that is “smart” insofar as it is “intelligent” have become established in many products. Material concept and properties

Materials can respond to light, heat and electrical current if they are equipped with photo-, thermo- or electrochromic pigments, lacquers, or gels. Inorganic metal oxides (e.g., zinc oxide, vanadium oxide), polymer blends or liquid crystals that do not immediately change from the crystalline to a liquid condition when heated are some of the typical materials with thermochromic properties. In particular thermotropically induced hydrogels for sun protection are the subject of current research projects. Coating systems and pigments with thermochromically functioning qualities have been on the market for some time now. They are available in powder or liquid form and can easily be applied to most material finishes.

145 Multifunctional materials

Properties  automatically adapting translucency // respond to light, heat and electrical charge // display function Sustainability aspects  improved climatic conditions with no consumption of energy // no need for elaborate control systems

Color and transparency-changing materials and colors. A change in black below the reaction temperature, through the colors of the rainbow from brownish red to blue, is typical. Under UV light the effect may become instable.

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Reversacol Photochromic colors react to UV radiation and change their color reversibly. A wide range of products featuring 20 standard colors for products such as sunglasses, nail polish, sportswear and transparent sun protection is available under the Reversacol brand.

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Color and transparency-changing materials can be used in fashion, wallpaper, magazine and furniture finish design. Under the influence of light, thermochromic glass coatings change their translucency with regard to solar radiation and automatically adapt to climatic conditions. Incorporated in packaging film, thermochromic pigments can detect insufficient cooling in food transport.

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Dines  Artificial leather by Dines  changes its color when stretched. Materials such as these are known as mechanochromic materials.

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Chromicolor  These are pigments, lacquers and resins with thermosensitive properties. When exposed to heat the material becomes transparent. The temperature at which the material reacts can be set. Thermochromic resins can be combined with the usual molding compounds and processed to form plastic parts. The effect remains stable even when exposed to UV radiation.

Furniture that responds to heat (Source: Jürgen Mayer H.)

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LCR Hallcrest Liquid crystals are chemical compounds with the mechanic qualities of liquids and the visual properties of solid materials. They can change color when the temperature changes (thermochromic liquid crystal technology). The manufacturer specializes in the formulation and microencapsulation of liquid crystal compounds and the development of thermosensitive products, pigments, ink

Touch me - thermochromic wallpaper (Source: Prof. Zane Berzina; photo: N. Cox)

Artificial leather changing its color when stretched (Source: Dines France)

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Solid Poetry  In the Netherlands, concrete bricks that reveal special structures when it rains were developed under this name. The natural moisture uncovers hidden decorations in public spaces and footpaths and provides a new sign language of urban quality.

Concrete surface that reacts to moisture (Source: Solid Poetry ®)

The development of surfaces that repel water, grease, and oil started with Wilhelm Barthlott’s discovery of the lotus effect in 1992. He ascertained that it is not smooth surfaces that prevent dirt particles from catching, but rather a roughness in the micro or nano dimension.

Properties  hydrophobic (water-repellent) // lipophobic (grease-repellent) // oleophobic (oil-repellent) Sustainability aspects  less cleaning required // longer life span of surfaces

Material concept and properties

The roughness of the surface minimizes the material’s contact area, such that droplets of water, grease and oil do not stick. Hydrophobic surfaces have a contact angle of more than 90° and promote the formation of droplets, making dirt particles easy to wash off. Nowadays, dirt-repellent properties can even be created artificially by means of coatings (e.g. silanes) or special structures. As opposed to hydrophobic surfaces, hydrophilic surfaces do not repel liquids, which then spread over the surface as a thin film.

Dirt-repellent surfaces How hydrophobic and hydrophilic properties work, from Handbuch für technisches Produktdesign Hydrophilic coating

Hydrophobic material surface

Water film

UV Hydrophobic coating

Droplet formation

Photocatalytic coating UV Water film + decomposition of organic soiling Hydrophobic material surface

The ultra-violet rays in natural light de­­ compose organic soiling and make the surface hydrophilic (left). Rain spreads over the surface and removes the decomposed remains and mineral dust.

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Dirt-repellent surfaces are used wherever short cleaning cycles are advantageous. Glass materials with hydrophobic qualities are used in diverse ways in roof and facade construction. These coating systems can also be fully brought to bear in shower cubicles, winter gardens and vehicle windows.

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Products

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Pilkington Activ The glass with self-cleaning and hydrophilic properties has a nano titanium dioxide coating just 50 nm thick. It is available in thicknesses of 3–10 mm.

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Nanotol This coating by CeNano  lends material surfaces grease and dirt-repellent properties. It contains no organic solvents and is thus suitable for use both indoors and outdoors. Nanotol  can be applied to all kinds of materials and was optimized for use on painted surfaces, fiber-reinforced materials and textiles.

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Ceramic wall covering as a substitute bathroom tiles (Source: Marburger Tapetenfabrik, Evonik Degussa)

Dirt and water-repellent ceramic wall covering (Source: Marburger Tapetenfabrik; design: Sylvia Leydecker)

The properties of electrorheological and magnetorheological fluids can be influenced by applying an electrical or magnetic field, to which the fluids react such that their viscosity between liquid and solid can be controlled directly and infinitely. This makes them suitable for the control of clutches, brakes and valves.

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ccflex  ccflex  is a ceramic wall coating with water-repellent, chemically resistant and fireproof properties. The Evonik Degussa Creavis Research Center in Marl was one of the first buildings to be fitted with this nanoceramic wall covering, which is providing some competition for conventional tiles, especially in bathrooms.

Glass with self-cleaning and hydrophilic surface (Source: Pilkington)

Properties  react to electrical and magnetic fields // variable viscosity // caused by polarizable micro-particles Sustainability aspects  reduction in mechanical control // material-efficient constructions

The structure of a ferrofluid Particles can be suspended in non-polar solution

Particles can be suspended in polar solution

Electrorheological and magnetorheological fluids

Material concept and properties

When exposed to an electrical or magnetic field, initially random polarizable micro-particles in a non-conducting base fluid become aligned and form chains. Subsequently, the liquid’s flowresistance increases. Magnetorheological fluids can even solidify. When the field is removed, they collapse and regain their fluidity. Ferrofluids also contain particles that can be magnetized. However, they are smaller than 10 nm, meaning that unlike magnetorheological fluids, when exposed to a magnetic field their viscosity changes only minimally. They typically form spikes and urchinlike structures in particularly strong fields. These are also called Rosensweig instabilities.

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Both ferrofluids and magnetorheological/electrorheological fluids are seen in technological fields as components of a system. They are used as vibration dampers in clutches, brakes, engine mountings and shock absorbers and enable switchable valves. Moreover, ferrofluids are used in computer hard disks and speakers for cooling and insulation. In medicine, they support the administration of active agents in chemotherapy, so that patients are treated far more gently. In mining, the specific alteration of viscosity and density is used to separate solid materials. Furthermore, magnetorheological fluids can be used in the construction of earthquake-proof buildings and bridges. Coating systems with ferrofluids are also used for radiation absorption in the aviation industry. Other fields of application range from artificial hearts and measuring technology to sculpture. In the field of optics, the particles in the fluid can be used specifically for light refraction.

absorbers, ERF can provide both comfort and safety, as within a fraction of a second the shockabsorbing effect is adjusted to the respective conditions, making it possible to optimally align the undercarriage with the speed and road surface. This effect can also be employed in fitness equipment. Here, the electrorheological damper replaces the stack of weights and enables the training program to be individually adapted to the needs of the user. Ferrotec For test purposes, Ferrotec GmbH is marketing a training pack containing a 50 ml bottle of ferrofluid, a glass inspection container with a special ferrofluid and a contrast fluid, as well as magnets, a syringe, pipettes and aluminum bowls, so that users can get to know the fluid’s special properties.

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Fitness machine based on an electrorheological fluid (Source: Fludicon)

Phase change materials (PCM), which can release heat to their surroundings during the transition from a liquid to a solid state, are known as hand and pocket warmers. For several years scientists have been researching new uses in the building sector. In 2009 PCM products were nominated for the Deutscher Zukunftspreis (German Future Award). Material concepts and properties

Microscopically small plastic spheres, the cores of which hold a storage medium made of waxes, impact on the ambient temperature by counteracting great fluctuations in temperature such as excessive heat in summer and a hefty drop in temperature in winter. Rising temperatures cause the wax to melt; heat is absorbed. If the temperature drops, the

RheOil Fludicon GmbH is the source of the world’s only commercially available electrorheological fluid. The company specializes in the development and sale of industrial products and systems that in terms of function are based on electrorheological fluids (ERF). Its product range includes dampers, clutches and actuators. In automobile shock

The structure of an electrorheological fluid (Source: Fludicon)

Properties  microspheres with waxes // natural air conditioning // switching temperatures: 23°C, 26°C // heat storage capacity: 110 kJ/kg Sustainability aspects  pleasant and healthy room climate // energy-efficient air conditioning // optimized heat insulation

Phase change materials (PCM)

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reverse process takes place. The wax solidifies and releases heat. When used in the building industry, microencapsulation allows the melting point to be set to the specific use. Switching temperatures of 23°C or 26°C are available on the market. The heat storage capacity is a continuous 110 kJ/kg. Use and processing

Latent heat accumulators can be integrated in a wide range of materials such as chipboard, wall plaster, gypsum and construction panels and have a positive influence on the ambient temperature. As a consequence the cost of air conditioning can be reduced considerably and, according to the manufacturer’s calculations, the additional costs can be amortized after no more than five years. A minimum life span of 30 years is expected. Researchers at the Fraunhofer Institute are currently developing a cup that is equipped with PCM in order to enable users to enjoy a hot or cold drink at the right temperature.

Multifunctional materials

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Lebast  is a loam construction panel equipped with PCM waxes, which despite its thin panels (14/22 mm) is able to increase the heat storage capacity several times over and protect buildings from overheating in the summer. The surface of the gypsum construction panels is balanced at all times.

Gypsum machine-applied plaster with PCM (Source: Saint-Gobain Weber)

Products

With regard to skiwear in particular, manufacturers are currently working on products that protect athletes from severe cold through the use of latent heat accumulators. In the construction industry there is already a wide range of PCM products available from different brands:

Microscope image of PCM in plaster (Source: BASF press photo)

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PCM SmartBoard is a gypsum construction panel for dry construction, which is equipped with phase change materials. With a thickness of 1.5 cm it has a heat storage capacity comparable with that of a concrete layer at least 14 cm thick or a 36.5 cm-thick vertical coring brick wall.

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Plaster with integrated PCM (Source: DZP)

Gypsum machine-applied plaster with PCM (Source: Saint-Gobain Weber)

maxit clima 26  refers to machine-applied gypsum plaster with a temperature-regulating function that lends itself to direct processing on the building site and as dry mortar. If 30% PCM is integrated in a 3 cm-thick layer of plaster, the heat storage capacity is comparable with an 18 cmthick concrete wall or a 23 cm-thick brick wall. Integrating phase change material in the green aerated concrete CelBloc Plus prevents heat escaping through the stone and reduces temperature fluctuations on the inner wall. Furthermore, the building material provides sound heat and sound protection, as well as fire prevention properties, not to mention eco-friendly properties to regulate humidity.

Team Germany, Solar Decathlon 2007, using phase change materials (Source: TU Darmstadt)

“Come, let us make bricks and burn them … and let us build for ourselves a city, and a tower whose top will reach into heaven.” The “Tower of Babel” in the Bible, shows that loam has been in use for thousands of years and even has potential for the construction of tall buildings. Given the fact that it is readily available and easy to process, and on account of the pleasant ambiance in loam buildings, the material is currently experiencing a renaissance. Material concept and properties

Loam is a very good heat accumulator that tends to absorb moisture and then release it again, giving it a stabilizing effect on the indoor climate. In summer rooms are cooled down while in winter the material prevents the air from drying out. In addition, loam filters toxic and odorous substances out of the air and has a pest-repellent effect. Its sound-absorbing qualities are remarkable. The fact that only very little primary energy is needed for the material’s processing, and that it can be recycled, are further qualities that make loam a sustainable material.

150 Multifunctional materials

Properties  absorption and release of moisture // stabilizing effect on ambient temperature // high heat storage capacity // sound-absorption // filtering of toxic and odorous substances // mold-resistant Sustainability aspects  natural building material // positive impact on room climate // recyclable // kind to the skin and environmentally friendly

Loam Project “The Tower of Bhaktapur”

Use and processing

The processing of loam is easy and cost-effective. Either prefabricated loam bricks or loam construction panels are used, or the natural material is molded into wooden casing by means of ramming devices. As the material cannot be permanently exposed to moisture, it is usually coated with a protective plaster layer or protected from damp weather by means of outer cladding. Given its ecological qualities, in recent years several buildings have been constructed with this material.

Tower of Bhaktapur (Source: Atelier Rang)

At a time when the German building sector is importing bricks from Holland and Poland, cement from Spain, steel and marble from India, aluminum from Brazil, and timber from Canada and tropical rainforest regions, the use of local building materials and local recycling seems to be one of the coming trends in ensuring the sustainable use of material resources. Roy Antik (Development Manager Sustainability at the Swedish construction group Skanska), for example, said in October 2009 that Skanska was planning to reduce its consumption of energy and resources by 50% over the coming years. In this context, Atelier Rang in Frankfurt conducted a very interesting building project using local loam from the excavation of the foundation soil for a tower in Nepal. When building the “Tower of Bhaktapur”, however, they not only aimed to extract all the building materials from the foundation soil, they also relied heavily on a combination of Hessian building culture and the centuries-old craftsmanship of the Newars. To this end different shapes of Frankfurt brick were exported to Nepal, but the material was produced locally. Even the bamboo for the scaffolding was sourced from a grove in Bhaktapur. Described by the architects as a “brick sculpture”, the building could spark the renaissance of bricks burnt from local loam. There are many parallels with the architectural history of Hamburg and Amsterdam.

151 Multifunctional materials

Ait Benhaddou in Morocco with walls made of fiber-reinforced loam

Loam plaster (Source: Hock ProCrea)

Loam building elements (Source: Hock ProCrea)

Green roofs, facades covered in plants, and green interiors are currently some of the most popular design means in contemporary architecture. In particular mosses, which can even be found outside their natural habitat in wall and plaster joints on old walls, are used because they are ideally suited to absorbing health-damaging fine particles.

Properties  absorbs ultra-fine particles in the air // no roots // water storage capacity // stabilizing effect on room climate Sustainability aspects  method for absorbing fine particles // natural room climate // sound-absorbing qualities

Material concept and properties

As opposed to flowering plants, mosses have no roots and absorb nutrients from the air. This allows them to grow on cliffs and roofs. With their extremely large surface they can bind particles electrostatically and then convert them into plant mass by metabolic processes. This way, when used outdoors the supply of nutrients is guaranteed for lengthy periods of time. In addition, bacteria that live in the mosses absorb the organic parts of fine particles. Given their great water storage capacity mosses have a positive impact on room climate.

Moss

Use and processing

With a view to taking advantage of the fact that mosses bind fine particles, several companies have launched mats with integrated moss. These can be used for a wide range of purposes and are particularly suited to roadsides, noise protection walls and roofs. Moss mats are delivered in rolls, cut to size, and attached mechanically. Given their low net weight, no additional structural elements need be installed. In interiors, irrigation is required for partitions and for plant-covered walls.

“Mossy Hill” installation (Source: Makoto Azuma)

“Time of Moss” installation (Source: Makoto Azuma)

152 Multifunctional materials

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Enka  -Moss This moss mat consists of a filament structure, moss shoots and a storage fleece. Fine particles are retained in the mosses and are not released into the environment again, even during dry weather.

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Terramac  This spacer fabric is ideally suited to moss installations for interiors. It consists of the biopolymer PLA and is sourced from natural biomass.

“Mossy Hill” installation (Source: Makoto Azuma)

Moss mats in use in City Parkhaus in Heilbronn (Source: Xero Flor International, Wiedemann + Schweizer Landschaftsarchitekten)

Zeolites are minerals with a regular hollow interior structure and porous surface. When exposed to heat they release water, appearing to boil before eventually melting into a small white glass bead. There are different zeolite structures in nature. Depending on their inner geometry they are divided into leaf, fiber and cube zeolite.

Properties  large interior surface // porous structure // high moisture absorption capacity // release when exposed to heat Sustainability aspects  filter material // binding of odorous substances // improved room climate

Zeolites The broken natural stone is clinoptilolith, a high-purity natural zeolite that is sourced from quenched volcanic glass. It is used in agriculture, pond building, cement production and in Japanese paper production. (Source: Claudia Arnold)

Material concepts and properties

In structural terms zeolites consist of SiO4 and AlO4 tetrahedrons that are configured in an alternating and recurring sequence. Given the numerous pores, channels and spatial structures, zeolites have an extremely large interior surface. This can reach levels of more than 1,000 m2 per

gram, meaning zeolites can absorb up to 40% of their dry weight in water or other liquids in a simple process and release it again when exposed to heat. The regeneration temperature is usually between 250 and 400°C, the inner structure is preserved, and the process is reversible.

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Multifunctional materials

With its special liquid-storing properties, zeolites are particularly suitable as drying agents. In washing powders they are used for water softening. They are also suitable for binding odorous liquids and are used in water filters. In the chemicals industry zeolites are primarily used for the fission of organic molecules. They are also employed to dry gases.

Spherical synthetic zeolite is an extremely hygroscopic fine drying agent and is contained, for example, in insulating glass. (Source: Claudia Arnold)

The escape of bonded carbon dioxide into the atmosphere when fossil energy sources are burnt is one of the main reasons for the climate change. Some 60% of the greenhouse gas effect caused by humans can be attributed to carbon dioxide emissions. Researchers the world over, are now working on discovering possibilities for storing free CO ² .

Properties  Carbon dioxide bonding in: cement // olivine // algae Sustainability aspects  reduction of CO² content in circulating air

Material concepts and properties

Scientists in California are currently working on a method of transferring the carbon dioxide emissions from a power plant to cement. The plan involves siphoning off some of the released carbon dioxide, and running it through seawater. Carbonates are formed from the magnesium and calcium dissolved in the water. The process can be compared with that responsible for the growth of coral. The waste heat from the power plant is subsequently used to dry the resulting muddy material into bricks and process into cement. Every ton of cement would bind half a ton of CO2 on a long-term basis.

CO2-absorbing materials

The effect could be intensified further by adding olivine, a shimmering green silicate material, with which we are familiar from the manufacture of heat-resistant glass. Scientists in the Netherlands have discovered that olivine can absorb CO2. As a component of concrete it could also help reduce the greenhouse effect. A number of pilot plants in Germany are taking a different approach and using micro-algae. Algae transform carbon dioxide into organic compounds through photosynthesis. The biomass gained this way can be used for cattle feed or the production of bio-diesel. Given the same cultivation area, at least 50 times more fuel can be produced from algae than from rapeseed.

Bitumen mat with integrated olivine granules

Olivine - shim mering green silicate material (Source: Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research)

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ProClimate  ProClimate  is a fireproof and watertight roof covering containing bitumen, a polyester reinforcement and olivine granules. In addition to

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being able to store CO2 the mineral lends the roof sheeting a green tone. Its life span is 25 years.

Leather car seats smell of almond oil, razor blades of lemon, and mattresses of aloe vera. This effect is made possible through tiny capsules that are almost invisible to the human eye.

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Properties  base for various substances // micrometer-sized // transparent // can be processed in spray or paints Sustainability aspects  display function, without elaborate electronics

Multifunctional materials

Material concept and properties

Microcapsules have a diameter of between several hundred nanometers and one millimeter. They are usually transparent and can be filled with a variety of gases, liquids and solids. Capsules with a porous nanosheath release the content over months in a constant concentration. If the capsule walls are rigid the effect is released when enough pressure is applied to burst the capsule. Scent microcapsules fulfill functions for improving air in rooms and indicating the current state of materials. They are integrated in coatings, sprayed onto textiles or applied through paint to metal surfaces. In principle, microcapsules can be processed like dry powder.

Scent microcapsules on CDs and DVDs. Advertising media have thus gained a new dimension in communication. Treating leather and furniture covers produces pleasant-smelling interiors. Scent integrated into razor blades indicates when the blade is worn out. A similar effect is possible in the wear and tear layers of tools.

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Scented microcapsules have been around since the 1970s. Back then they were used in carbon-free copy paper. Advances in nanotechnology have resulted in a far wider range of potential uses. By way of example, perfume oils can now be encapsulated, blended with colorless paint, and printed

Microcapsules for absorbing various substances (Source: BRACE GmbH ChemiePlastics-Esthetiques-Data System)

Titanium dioxide is known as a classical white pigment. However, reducing a TiO ² particle to the size of a few nanometers gives it a dirt-dissolving, UV-blocking and odorneutralizing effect.

Properties  dirt-dissolving // waterresistant // UV-blocking // disperses odors and toxins Sustainability aspects  decomposes environmental pollution // reduces cleaning intervals with its self-cleaning effect // lowers water consumption

Material concept and properties

Nano titanium dioxide acts as a highly reactive catalyst. Integrated in a material surface it decomposes organic dirt under the influence of light and breaks down odors, for example fatty acids, and pollutants such as nitrogen oxides, nicotine and formaldehyde. In a “cold combustion” process these are transformed into harmless substances and carbon dioxide. The titanium dioxide, which is transparent in nano dimensions, is not itself used up in the process, and continues to be effective for several years.

Nano titanium dioxide

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The photocatalytic effect of nano titanium dioxide was discovered back in 1967 in Japan, and since the 1990s has been used in marketable applications for tiles, roof tiles and panes of glass. In recent years wallpaper, partitions, carpets and paints have also

been equipped with nano titanium dioxide for indoor use. In the building industry, titanium dioxide particles are commonly integrated in gypsum boards. A number of large cities, such as Milan, have already attempted to integrate the pollutant-

absorbing effect of the particles in asphalt and cobblestones in order to purify the air. In wood preservers, nano titanium dioxide can also reduce bleaching and yellowing. In plastic film, it is said to protect foodstuffs from UV radiation.

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proSolve370e  In fall 2009 the first commercial use of the gasdecomposing facade element proSolve 370e  was reported in Perth. The decorative facade elements boast a coating containing nano titanium dioxide, which reduces air pollution. The concentration of volatile organic compounds is reduced just as much as that of nitrogen oxides. And quite incidentally, the aesthetic structures also conceal some of the architectural sins of the 1970s and 1980s.

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Air Clean   cobblestones The results of a study of sample surfaces with a photocatalytic effect that the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) conducted from 2007–2009 in various German cities reveal that the pollutant-reducing effect can also be transferred to concrete surfaces and cobblestones. It was discovered that when the sun shines, photocatalytic concrete products can contribute to a 70% reduction in nitrogen oxide.

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Air Clean  wall paint A paint for interiors has been launched, whose name is indicative of its effect. Research shows that when it is used, 99.9% of all nitrogen oxide and 65% of the fatty acids (kitchen smells) in the air are decomposed within 24 hours.

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duraAir  With its integrated nano titanium particles, this is the first carpet in the world capable of ridding interior spaces from odors and harmful formaldehyde. Household, animal, garbage, WC odors, as well as cigarette smoke and nicotine are all decomposed, enabling the carpet to create a healthy room climate.

Pollutant-absorbing cobblestones contribute to a reduction in nitrogen oxide

NOx NO x Organic polluants NOx NO x proSolve370e ® facade elements with air-purifying titanium dioxide coating (Source: elegant embellishments Ltd.)

Scratch-resistant helmet visors, bright white facade colors and flame-resistant electrical wires: silicon dioxide just a few nanometers in size displays extraordinary characteristics, which for years now have made it interesting for development departments.

Up to 70 % less NOX HNO3

H 2O Nitrates

Properties  dirt-resistant // scratch-proof // fireproof corrosion protection // highstrength // transparent surfaces Sustainability aspects  reduces tendency to wear out // increases life span due to flame-retarding properties // increases efficiency of solar panels

Nano silicon dioxide Material concept and properties

Scratch-proof wind protection made of coated polycarbonate (Source: Bayer Sheet Europe)

Nanocrystalline silicon particles are advantageous predominantly for the production of a transparent, scratch-proof and anti-corrosive protection for metal, glass and wooden surfaces, which is generally a lot harder than normal SiO2 and also affords protection from mechanical and

thermally induced damage. In addition, the transmission factor of glass with SiO2 anti-reflection coating can be considerably increased. Given the different refraction quotients of glass and air, transmission losses of up to 8% are normal.

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Anti-reflective coatings based on SiO2 particles are primarily used in panes of glass for solar panels and glass facades. The reflection losses are reduced by 2–8%. Fire prevention gels, in which nanostructured silicone dioxide particles are used as polymer fillers, serve to increase heat resistance and optimize the flame-retarding properties of cable sheathing, fuse boxes and power points; they are applied to wooden and plastic elements as a flame-resistant coating. They are known under the name “Nanoclay”. Fire protective gels also considerably improve the fire resistance of glazing. In the event of fire, a rigid foam layer is created on

Structure of nano quartz grid technology

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silicone dioxide SiO2. The high refraction coefficient makes it possible to reflect the majority of incoming light, so that reflections from interference can be eliminated. Possible applications are visors for motorcyclists’ and firefighters’ helmets. Non-reflective surfaces also increase the brightness of light diodes.

Multifunctional materials

the glass surface. When integrated in wall paints nano quartz particles considerably reduce the tendency to become dirty. Products

®

Nano-Quarz-Gitter  This facade paint with nano quartz particles clearly reduces any tendency to accumulate dirt. The particles are evenly distributed in a 3D grid structure, to which dirt, fine particles, and spores are far less likely to stick. Substances that nevertheless cling to facades in the short term are blown or washed away from the painted surface by wind or rain. The protective function and intensity of the color remain, and furthermore the brightness is significantly increased. The fact that it is easy to handle reduces the time required to apply the paint.

®

®

®

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Makrolon  AR This is a range of panels with a scratch- and chemical-resistant surface based on nano silicon oxide. The two-sided coating increases durability, improves UV stability and reduces long-term tarnishing and yellowing. The robust polycarbonate panels have a similar degree of hardness to glass, together with the typical impact resistance.

AR-hard  The AR-hard process developed by the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF) is used to manufacture anti-reflex coatings in thicknesses ranging from 0.8–4 μm, with scratch-proof qualities for optical components such as PMMA and PC. Thin layers of titanium dioxide are integrated in a layer of

The quartz-reinforced “matrix” structure

The antiseptic effect of silver has been known for 3,000 years. Nowadays, silver threads are used in textile fabrics and wound dressings to stop the spread of germs. Nano silver coatings increase the antiseptic effect of surgical instruments and implants.

Properties  antibacterial // germ-killing // costs depend on price of silver Sustainability aspects  antibacterial effect

Effect of AgPURE ™ in protective textiles

Micro organisms

Destroyed micro organisms Humidity

Ag+

Ag+

Coating < 10 μm Film Spun-bond non-woven

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Aerosil  Aerosil consists of finely fragmented silicone dioxide and improves the material quality of technical rubber objects and the flow behavior of various powders. It hardens paint against scratches, acts as a polishing substance for microchips, optimizes the flow behavior of toothpaste, and is also used as a pharmaceutical additive. As opposed to carcinogenic asbestos, with its needle-like structure, Aerosil features a rounded structure that poses no health risks.

Ag+

Nano silver

Material concept and use

Nano silver interrupts the metabolism of bacteria and effectively stops their growth and reproduction. When integrated in material surfaces (e.g., in refrigerators or on scalpels) silver ions even kill germs (up to 650 different bacteria) that have become resistant to antibiotics, thereby preventing life-threatening infections. Typical applications are medical containers, household packaging, tableware, textiles, bathroom fittings, refrigerators, washing machines, cement, door handles and wallpaper. At present the influence silver particles may have on water has not been clarified and for this reason the danger is to be reevaluated in US studies. Currently there are some 200 products on the German market containing

157

nano silver particles. Their price is determined by the price of silver. Products

Multifunctional materials

™

HyProtect One of the specialists in this field is Bio-Gate, a company that furnishes various materials containing nano silver to achieve long-term protection against bacteria and other pathogens.

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Bioni Hygienic  In 2008 the Fraunhofer Institute for Chemical Technology (ICT) received an award for the antibiotic use of nano silver in water-based paints. The paints developed in collaboration with CS GmbH prevent long-term mold formation and even kill the multi-resistant hospital bug staphylococcus aureus.

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AgPURE The antimicrobial additive AgPURE based on elementary silver can increase the hygienic effect of fibers, plastics, elastomers and paints used in a multitude of products.

Uvex sil-Wear 3 B vibatec with active antibacterial nano silver coating for fire department use (Source: UVEX Safety Group GmbH; photo: Jürgen Petzoldt)

That nano titanium dioxide is capable of freeing the surrounding air from pollutants and odors has been known for some time. In 2008, an Australian team of scientists from Brisbane also proved that tiny gold particles in the coatings of mediaeval church windows have the same effect. Mediaeval glaziers were thus among the first users of nanotechnology.

Reducing the number of algae with nano silver (Source: Boni CS GmbH)

Properties  decomposition of pollutants and odors // costs determined by price of gold // controls the effect of medicines // colors glass material Sustainability aspects  decomposition of environmental pollution

Material concept and properties

Under certain light conditions the particles produce a magnetic field that decomposes pollutants in the air and volatile compounds from paint or cleaning products. The electromagnetic field produced by the sun’s rays combines with the oscillations of the nano gold particles and produces a resonance oscillation. This intensifies the magnetic field on the surface of the gold particles up to 100 times, so that organic molecules from toxic substances are broken up in the air. As this process can take place at room temperature, beneficial industrial applications are possible.

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Nano gold

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use

Nano gold particles are interesting as catalysts for lowering the costs and adverse environmental effects of production processes. In 2009 scientists at the Massachusetts Institute of Technology (MIT) for the first time also used the different melting points of nano gold particles, being the carrier materials for diverse active ingredients, under infra-

red light to selectively treat cancer and Aids with a range of medicines at specific intervals, and to prevent dangerous side effects. Nano gold particles can also be dissolved in water and, depending on the particle size, make glass red, purple or blue for decorative purposes.

Multifunctional materials

The potential nanotechnology offers for creating new material properties become particularly clear in relation to paper. The nanostructuring of cellulose makes paper considerably more tear-proof, and special nanocoatings can lend paper and cardboard qualities resembling those of plastic and metal.

Properties  tear-resistant // absorbs pollutants // high strength // resistant to high temperatures Sustainability aspects  longer life span // absorbs pollutants // energy-storage medium

Material concepts and use

Tear-proof nanopaper One possible method of producing tear-proof paper was developed by the Royal Institute of Technology in Stockholm. It involves treating a cellulose pulp created from nanofibers with particular enzymes and pressing it through a very fine lattice structure under a pressure of up to 1,650 bar. After pouring the mass to form a thin film, it is then dried with the addition of solvents. The end result is extremely stable and very thin paper with a similar tensile strength to cast iron. One possible application would be as a substrate for computer chips. Pollutant-absorbing nanopaper Researchers at MIT are currently working on a mesh of nanowires that can absorb up to 20 times its own weight in impurities such as mineral oil from water. This would aid efforts to combat environmental disasters. As the nanowires remain stable even at very high temperatures, the oil absorbed could even be removed from the material by means of condensation processes and the nanopaper recycled.

Nanopaper How energy-storage nanopaper works (Source: Rensselaer Polytechnic Institute)

Supercapacitor

Battery

Current collectors

Li electrode

MWNTs

Cellulose

Electricity-storing nanopaper Researchers at the Rensselaer Polytechnic Institute report success in printing cellulose paper with aligned carbon nanotubes (CNT). The paper could be used as a rechargeable source of electricity (battery). A liquid salt that contains no water and is thus insusceptible to frost and to drying out serves as the electrolytes.

RTIL CI– N

+

—

MWNTs = multiwalled nanotubes RTIL = Room temperature ionic liquids

+

N

+

—

Bicycle inner tubes that repair punctures themselves and coatings for hulls that are capable of sealing cracks on their own: scientists all over the world are advancing the development of self-healing materials. The first substances are about to be launched on the market.

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Properties  protect from corrosion // more durable Sustainability aspects  prolonged service life

Multifunctional materials

Material concepts and use

Scientists at the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) developed small liquid-filled capsules with a diameter of 200 nanodimensions, which can be added to the galvanic coating of a metallic car body element. If the surface cracks, the capsules burst, releasing the liquid containing the chemical, which protects the material from oxidization (rust). To lengthen the lifecycle of layers in the short term, the nanocapsules can also be filled with lubricants.

Self-healing materials

The aim of using microcapsules that contain a dual-component adhesive and can be integrated in a coating material is to prevent corrosion on damaged hulls. If the surface gets scratched, the capsules burst, the components blend and the adhesive hardens. The gap is sealed before the highly corrosive seawater can enter the hull. After its successful market launch in the shipbuilding industry, the intention is to transfer the principle to offshore wind farms, bridges, pipelines and drilling rigs. A self-healing bioconcrete that, after hardening, seals any cracks is currently being developed at Delft University of Technology. Moisture that penetrates the concrete through a crack leads microorganisms to start producing calcium carbonate. The yeast extract and peptone required for this are added to the concrete before it is set. The market launch is planned for 2013.

Nanocapsules containing liquid in a galvanic coating (Source: Fraunhofer IPA)

Golden Gate Bridge - bridges are potential application areas for self-healing materials

160 Energy-generating and light-influencing materials

Photovoltaic Materials…164 — Thin-film Solar Cells…165 — Multiple Solar Cells…166 — Black Silicon…166 — Green Algae…167 — Thermoelectric Materials…168 — Ferroelectric Polymers…169 — Lightemitting and Luminescent Materials…170 — Light-emitting Diodes (LEDs)…172 — Organic Light-Emitting Diodes (OLEDs)…173 — Multitouch Films…174 — Retro-reflective Materials…174 — Translucent Materials…175 — Metamaterials…176

— 07 —

161 Energy-generating and light-influencing materials

162 Energy-generating and light-influencing materials

Whereas homeowners are placing ever greater importance on reducing energy consumption by using regenerative energy sources, it is primarily architects who are encouraged by the development of luminescent, translucent, and even light-emitting materials. While scientists are working on using entire building facades as energy sources by printing photoelectric organic dyes on them, flexible thin-film solar cells have already found their way into outdoor gear and the fashion industry. The microstructure of silicon is intended to considerably increase the effectiveness of solar cells. Ferroelectric polymers could replace coolants and compressors in refrigerators. Green algae are hailed as an alternative future energy source. The recent past has seen several extremely interesting developments, primarily in the field of light-generating and light-influencing materials. A Hungarian architect having made concrete transparent, this effect has now been transferred to wood. By embedding micro-glass capsules in a stone mass, researchers at the University of Kassel have produced reflective concrete, which is intended for use as a large lighting element or to mark potentially dangerous corners and edges. Moreover, in future, flexible organic LEDs will enable walls in business or home environments, as well as vehicle and display windows, to become freely programmable monitors.

163 Energy-generating and light-influencing materials

Translucent concrete wash basin (Source: Robatex)

Not least of all thanks to very generous state subsidy programs, in recent years photovoltaics have gained considerably in importance. The photovoltaic effect is generally understood as the conversion of the sun’s rays into electrical energy. A photovoltaic facility consists of a large number of solar cells that are connected to each other and to a solar generator. Various materials are able to generate electricity, including silicon, various other semiconductors such as CIGS, GaAs and CdTe, as well as organic hydrocarbon compounds and pigments. Material concepts and properties

Silicon The most important material for photovoltaics is silicon. Whereas crystalline silicon is primarily used in the thick-film sector and efficiency rates of 18–20% are now realistic, silicon with an amorphous structure is now used in thin-film applications. Today, thanks to their high level of silicon, monocrystalline photovoltaic modules are the most effective. They can be recognized by their black color and are popular in balloon construction in roofs. A bluish color and crystalline structure point to polycrystalline silicon. Thanks to its good price/performance ratio, it is the most frequently used

Alternative semiconductor materials Alongside silicon, there are other materials with semiconducting properties, including gallium arsenide (GaAs), cadmium telluride (CdTe) and copper indium disulfide (CIS). While the use of GaAs modules, which boast efficiency rates of up to 30%, is limited to niche applications on account of the high production costs involved, by way of comparison CdTe modules can be produced very cost-effectively. Research into increasing the efficiency rate is currently underway. Solar module manufacturers are currently hoping for good results in particular from copper indium gallium sulfur selenium compounds (CISG solar cells). That said, these compounds are sensitive to moisture. Organic hydrocarbons Plastic solar cells generate electricity by means of a two-layer hydrocarbon structure. Given the low production costs, high electricity yield in thin film systems, environmental compatibility and the option of colored designs, plastic solar cells are said to have enormous future potential. One economical application of solar cells with organic hydrocarbons is currently not yet viable due to their low efficiency rate (around 5 %) and limited long-term stability.

164

Properties  lightweight construction potential // porous material structure // extreme rigidity // corrosion-resistant

Energy-generating and light-influencing materials

Sustainability aspects  energy sourcing without environmental damage // possibility of constructing PlusEnergy buildings

Photovoltaic materials Organic dyes Using a principle similar to photosynthesis, organic dyes such as chlorophyll convert sunlight into electrical energy. To obtain this energy, the structure of what is known as a dye-sensitized solar cell is used, in which a charge exchange takes place between two parallel glass electrodes. The dye is on the surface of the side facing the sun. As the production techniques have long been known from glass processing, economical uses of these cells are expected to be possible in the future. Moreover, the color and transparency of the cells can be varied and adapted to particular uses, so that in future architectural design will no longer be negatively affected by photovoltaic systems.

The Heliotrop ® was the first building in the world to produce more energy than it consumes inside (Source: Rolf Disch SolarArchitektur)

Solar panel (Source: Bayer MaterialScience)

Organic solar cell module (Source: Fraunhofer Institute for Solar Energy Systems (ISE))

165 Energy-generating and light-influencing materials

Proportion of photovoltaics in Germany in 2008 Photovoltaic materials used in PlusEnergy buildings (Source: Rolf Disch SolarArchitektur)

27,300 biomass 21,300 hydraulic energy

4,000 photovoltaics 18 geothermal energy

Transparent pigment solar module produced using the screen printing process (Source: Fraunhofer ISE)

40,400 wind energy

While thick-film solar cells based on silicon wafers are now widespread, thin-film technology is creating new applications for solar technology even outside the construction sector. Thin-film solar cells are flexible and up to 100 times thinner than the classic wafer-based cells.

Sustainability aspects  use of solar energy to run mobile systems

Material concept and properties

The first attempts to produce thin-film solar cells were made using evaporating techniques. Initially, materials other than silicon were used as semiconductor materials and were transferred directly from the gas phase to a base surface. However, output was extremely low and control of the process temperamental, meaning that these materials offered no significant economic competitive edge over conventional solar cells. Nowadays, various printing techniques are employed in the production process and films with a thickness of less than two micrometers produced. The physical properties and efficiency of the new generation of thin-film solar cells differ depending on the materials used for the semiconductor and substrate, the printing technique selected and the thickness of the film. use

Thin-film solar cells are now used for more than just industrial applications, for example, for outdoor gear, textiles and sports equipment. This is primarily related to their attractive efficiency rates.

Thin-film solar cells Production processes for thin-film solar cells 1st wave Silicon / waferbased cells

2 nd Wave Thin-film solar cells (vacuum technology)

3rd Wave Printed thin-film solar cells

Process

Silicon wafer processing

Vacuum methods (e.g. sputtering)

Roll-to-roll printing techniques

Process Control

Fragile wafer

Narrow process window

Integrated reproducibility (bottom-up nanotechnology)

Process Yield

Robust

Susceptible

Robust

Pro rata use of materials

30 %

30-60 %

Over 97 %

166 Energy-generating and light-influencing materials

The SolarGrass project made use of new technology involving inter-weavable photovoltaic fibers, which produce a textile-like fabric. (Source: Bauhaus University, Weimar; photo: Team SolarGrass)

However, their low weight plays a key role in terms of mobile applications. Curtains with integrated solar cells, bags and rucksacks with solar film sewn into them and tent canvas with integrated solar cells and storage device: new thin-film solutions can supply an MP3 player, PDA or even a laptop with electricity anywhere, at any time.

While the biggest complaint of users and manufacturers of solar modules is the low efficiency rate of conventional solar cells, which is generally under 20%, scientists are already developing a solution. It is thought multiple solar cells will enable an efficiency rate of more than 40% in the future, thereby considerably improving the efficiency of photovoltaic systems. Material concept and properties

The high efficiency rate is the result of a special structure, in which several solar cells are arranged in layers, one on top of the other. Incident sunlight is initially bundled by a concentrator lens and subsequently split into several wavelength ranges in a spectrum. The layers of solar cells perfected for each wavelength convert the sunlight into electrical energy. During a test using this energy conversion technique in January 2009, researchers at the Fraunhofer ISE achieved an efficiency rate of 41.1%. The semiconductor materials GaInP/ GaInAs/Ge (gallium indium phosphide/gallium indium arsenide/germanium) are used for multiple solar cells.

Bag with thin-film solar cells (Source: Sunload)

Sustainability aspects considerable increase in the efficiency of solar cells

Multiple solar cells use

Multiple solar cells are intended to optimize the efficiency of photovoltaic solar energy facilities in the future and further increase the proportion of solar energy in the energy mix. Scientists are working to convert the technology into a marketable product as quickly as possible and install it in solar power plants.

Multiple solar cell with an efficiency rate of 41.1 % (Source: Fraunhofer ISE)

Properties  light-absorbing needle structure // increases the efficiency of solar cells // special cohesive properties (hook and loop fastener) Sustainability aspects  increases the efficiency of solar cells // bonds without adhesive

Black silicon

“Black silicon” is the term for a light-absorbing layer of silicon needles roughly 100–300 nanometers thick and up to several micrometers long which, alongside unusual optical qualities, displays very good cohesive properties. It is sometimes termed “silicon grass” because of its similarity to a lawn’s structure and is actually an unwanted byproduct of dry etching. Material concept and properties

Its special ability to absorb light was discovered back in 1999. Rays of light hitting the surface are reflected back and forth several times on the

rough surface structure of the silicon needles, which catch them. The needles absorb 95–98% of the light. If you press two layers of black silicon together, particular cohesive properties emerge. The 1–2 million nanoneedles per square millimeter hook onto each other and can repeatedly be pulled apart and reattached, similarly to the hook and loop fastener principle.

167 Energy-generating and light-influencing materials

hook-and-loop fastener effect is expected to find applications in the electronics industry and make micro-components strongly cohesive. With black silicon, small components could be attached before adhesive is used and thin wafer plates held in position during the processing stage.

Light-absorption by silicon grass layers

use

This light-absorbing effect is intended for future use in the manufacture of so-called “black solar cells”, which will be almost twice as efficient as today’s cells. Whereas the solar cells being developed today have an efficiency rate of 40–50%, at best, the use of nanoneedles will raise it to up to 80%. Alongside their use in energy generation, silicon needles can also serve as emitters for rays to control satellites. NASA is researching ways of using them to detect thermal rays, which are reflected by particles in the atmosphere. The

Hook-and-loop fastener effect (Source: TU Ilmenau)

The presence of algae in water is regarded as a sign of pollution. However, this looks set to change in the future, as scientists are currently discussing the possibility of using algae as an alternative source of energy, of obtaining biodiesel from them or using them to produce hydrogen. Moreover, Swedish researchers have successfully made batteries based on Cladophora algae.

Sustainability aspects  natural hydrogen production in bioreactors // fuel cells drive electric motors without producing pollutants // electrode material for batteries based on fast-growing algae // energy-efficient battery production

Green algae Structure of an algae battery

Filter paper soaked with electrolyte

Cellulose/PPy composite

+ — Cellulose/PPy composite Pt foil

Material concepts and use

Hydrogen production Hydrogen is considered an environmentally friendly energy source for operating electric motors. In a fuel cell hydrogen reacts with oxygen to make water. In so doing, it generates electricity without producing any harmful substances. For the successful operation of a fuel cell, the hydrogen must also be produced using an environmentally sound process. Green algae offer considerable potential here. With the help of the enzyme hydrogenase, they separate water into oxygen and hydrogen. They obtain the requisite energy through photosynthesis. When put on a sulfur diet, the algae increase their metabolism. They

produce excess energy, which is disposed of in the form of hydrogen. By genetically modifying the green algae Chlamydomonas reinhardtii, scientists have succeeded in increasing their natural hydrogen production by a factor of 13, meaning that 200 liters of algae culture could generate around 50 liters of hydrogen per day. Scientists intend to make large-scale hydrogen production suitable for industrial purposes using bioreactors with improved lighting based on natural daylight. They hope to be able to control the hydrogenase with the help of bacteria.

Algae battery As energy stores in the form of batteries too, Cladophora green algae offer great potential for integrated electronic components in wallpaper, intelligent textiles, and medication packaging. In 2009, Swedish researchers successfully developed a battery based on a nanostructure of algae cellulose without great energy consumption. The structure has a surface 100 times greater than that of paper cellulose, which makes the surface of the algae particularly suitable as a base material for the conductive polymers. The scientists covered the nanostructure with a 50 nanometer-thick layer of the polymer polypyrrol, and created a completely new, lightweight electrode material, with a high charging speed for rechargeable batteries. They completed as many as 1,000 charges. The simple production method would prove advantageous especially in developing countries and provide competition for the hitherto standard lithium-ion batteries.

168 Energy-generating and light-influencing materials

Hydrogen forming in a sealed C. reinhardtii culture cultivated under low-sulfur conditions (Source: Prof. Thomas Happe, Ruhr-Universität Bochum)

Many scientists have a vision of using the waste heat from power plants and vehicles to generate electricity. In the process thermoelectric materials are intended to be used, which, when there is a temperature gradient between one material surface and the next, are capable of generating a flow of electrical current. Concepts for producing thermoelectric materials with sufficient efficiency rates are currently still being developed. However, advances in nanotechnology could lead to a considerable increase in efficiency.

Properties  generate energy through difference in temperature // use waste heat from power plants and vehicles // efficiency rate: 3-8 % Sustainability aspects  increased efficiency of power stations and engines by utilizing their waste heat

Thermoelectric materials

Material concept and properties

Thermoelectric generators consist of at least one pair of differently doped semiconductor materials (p-type and n-type doping). They are connected with each other at one point such that, given a difference in temperature between one side and the other, an electron flow is generated. This depends on the temperature and differs considerably depending on the materials used. Bismuth telluride alloys (e.g., BE2Te3) are the most widely used for applications at room temperature. For higher temperatures, thermoelectric generators (TEG) consist primarily of SiGe or PbTe with efficiency rates of 3–8%. To achieve high voltages, the elements can be configured in a series circuit between the cold and warm side. The reverse effect is also possible. By applying an electrical charge, thermoelectric generators can be used to generate minor differences in temperature.

This panel reactor ensures optimum light management in algae cultivation (Source: Florian Lehr, Karlsruher Institut für Technologie KIT)

Structure of a thermal element —   n-conductor +   p-conductor

Ceramic

Metal bridge

—

+

169 Energy-generating and light-influencing materials

use

Prototypical thermoelectric generator (Source: University of Bremen)

Nowadays, thermoelectric generators are used wherever the achievable cooling effects generate value added with just a minor difference in temperature (e.g., cool bags, the cooling of electronic devices). By increasing the efficiency, it seems that in future it will be possible to directly transform waste heat into electrical energy. In space travel too, nuclear-powered thermoelectric generators based on PbTe or SiGe are used as an energy supply.

Today more than ever, energy consumption is the prime consideration when choosing a refrigerator. Manufacturers therefore try to attract customers with energy-efficiency ratings of A++. The volume of the compressor is also increasingly seen as a measure of quality, which inspired American material experts to develop a new synthetic material.

Material concept and properties

By applying an external flow of current, what are known as polar plastics with ferroelectric properties are intended to generate a cooling effect, and thereby make liquid coolants and the noise made by complicated cooling technology redundant. In the electrical field, the molecules of the new plastic change from being in an unorganized state to an organized state, producing heat in the process. The temperature of the material drops, which, with heat exchangers can be used to cool the surrounding air. By applying a charge, a fall in temperature of around 12 degrees has already been recorded in tests.

Prototypical thermoelectric generator (Source: University of Bremen)

Properties  polymers used for cooling purposes // substitute for liquid coolants // slimmer cooling devices possible Sustainability aspects  substitute for complex cooling technology

Ferroelectric polymers

use

Today’s cooling systems are based on the principle of gases absorbing heat when pressure is reduced. Complicated technology is required which in future could be simplified considerably by ferroelectric plastics. Flat refrigerators with

no compressors or pipes are even conceivable, for example, which would give product designers far greater leeway for making their ideas reality. Air-conditioning systems would be far more efficient, and the new materials could also be

used to cool computer chips. Further potential areas of application are self-cooling packaging, and functional clothing for athletes and firefighters.

Light-emitting materials have always fascinated designers and architects. Material concept and properties

Luminescence is the result of a physical process in which external energy excites a molecule into a higher energy state for a short period. When it returns from its excited to its basic stable state, it emits particles of light, which we see as electromagnetic radiation. In physics, distinctions are made between the following types of luminescence, based on the type and quality of excitation: – Electroluminescence originates from excitation following the effect of an electric field or from the flow of an electric current. Technical applications of the effect are found in lightemitting diodes (LED) and organic light-emitting diodes (OLED). – The cathode ray tube developed by Braun, the heart of the classic tube television and scanning electron microscope (SEM), displays the effect of cathode luminescence. A beam of electrons hits the surface of a material, whereupon light is emitted.

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Sustainability aspects  reduced energy costs

Energy-generating and light-influencing materials

Light-emitting and luminescent materials

– In photoluminescent materials, momentary excitation by a beam of photons or light generates the luminescent effect. Whereas with fluorescence the emission of light stops shortly after the excitation ends, phosphorescent materials can emit light for hours afterwards. Typical applications are signs with safety notices and self-luminous bait for fishing. – Excitation as the result of a chemical reaction is known as chemoluminescence. This is used, for example, to analyze blood. Glow sticks are a well-known example of a product using this technology. The emission of light can last for just a few minutes or several hours. – Bioluminescence is also based on a chemical reaction. However, it is not artificially produced, but takes place in a living organism as a form of camouflage or a threatening gesture. The phenomenon is common primarily among deep sea fish and some insect species (e.g., glowworms). Fireworms, for example, color the sea a luminous green when they are looking for a mate or want to fend off troublesome attackers. In 2009, scientists discovered seven new species of fungus with self-luminous properties. – Thermoluminescence occurs following excitation by means of thermal energy. It is used, for instance, in archeology to determine the age of excavated pottery. In technical terms, the functioning of light bulbs is based on this effect.

Textiles with photoluminescent properties (Source: Kathy Schicker)

Photoluminescent particles for concrete products (Source: Ambient Glow Technology)

“Lo Glo” furniture range with luminescent qualities (Source: J. Mayer H. Architects, Vitra Edition 2007)

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use

Photoluminescent and electroluminescent materials currently have the greatest significance for architects and designers. They include luminescent metals, textiles and luminescent particles integrated in stone. The first self-luminous book cover, made using electroluminescent film, was presented in 2008. Now, even 3D moldings with electroluminescent properties can be made.

Energy-generating and light-influencing materials

Products Light-conducting Materials

products

®

Luminal  A coating for aluminum surfaces with luminescent properties promises to help people avoid hazards following a power cut in public buildings. The sheets’ luminescent effect lasts for about an hour. The finish is resistant to mechanical impact, meaning that the sheets can be rounded and shaped. Luminal products satisfy fire prevention class A1 standards.

™

Ambient Glow Technology – AGT These photoluminescent particles are suitable for use in concrete, cement, terrazzo and stucco. Just ten minutes of light is sufficient to generate a luminescent effect lasting up to 12 hours. DigitalDawn This textile uses a printed electroluminescent coating to show a floral pattern after the room darkens.

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Luminex  Luminex  is a textile consisting of a light-conducting fabric and illuminating yarn. Light of various colors is reflected on the surfaces and conducted through the fabric. It emerges at various spots and creates interesting optical effects. They are especially interesting to furniture and fashion designers.

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Makrofol  Makrofol  by Bayer is a light-conducting film made of polycarbonate, containing fluorescent pigments. Incident light of longer wavelengths is reflected within the film and emerges through the edges. For this reason the material displays a clearly visible brightness at the edges. Its other properties are good resistance to heat and very good graphic quality. It is just as suitable for external effect applications as it is for identification cards and passports.

®

Room with luminescent aluminum panels (Source: Novelis Deutschland)

Uses of Luminex ® (Source: Luminex ®)

Textile with printed electroluminescent coating (Source: Merlin Dunkel)

The darker a space becomes the brighter the DigitalDaw n window blind will glow. (Source: loop.pH)

In design and architecture, lighting systems with LED technology have become increasingly important in recent years. This is due on the one hand, to their high energy efficiency in comparison with conventional lighting systems, spelling considerable reductions in power consumption, and on the other, to the fact that programming options with regard to color and color gradients are particularly interesting. Material concept and properties

The luminescence effect in LEDs is produced by transforming electrical energy into light using a semiconductor material. This prevents unnecessary heat generation, which has a positive effect on energy efficiency. The choice of semiconductor material (e.g., gallium phosphide, silicon carbide) enables the spectrum of an LED, and as such the color of the light emitted to be determined. LEDs can be controlled quickly. To make optimum use of the light, lenses made of glass or optical plastics are employed to direct the rays. LEDs are available in different sizes and models, those of 5 mm in diameter being the most common. Based on a light yield of between 30–80 Lumen/Watt, the different systems have a life of 30,000–100,000 hours.

172 Energy-generating and light-influencing materials

Properties  high energy efficiency of LEDs average life span 50,000 hours // light yield 30-80 Lumen/Watt (trend clearly rising) // programmable color gradients Sustainability aspects  long life span // high light yield, but low energy consumption // no unnecessary heat generation

Light-emitting diodes (LEDs)

use

Nowadays, apart from being used in electronic devices and room lighting, LEDs are employed in interior design, where they create a special ambience with changing light colors. Given their increased light yield, LEDs are now suitable for illuminating lay-bys, underground car parks and parking decks and are used to light translucent facade elements from the rear. By way of example, at its HQ in Leverkusen Bayer installed the world’s largest media facade to date, comprising 5.6 million LEDs across a surface area of 18,000 m2. In furniture design in particular there have been several interesting designs of late. The “Table Manner Table”, for example, reminds guests who are reluctant to put away their cell phone about good table manners.

Bayer media facade with 5.6 million LEDs (Source: Bayer MaterialScience)

Lamp using LED technology (Source: Maria Hamprecht)

Semiconductor material and color of light red and infrared

aluminum gallium arsenide (AlGaAs)

red, orange, yellow gallium arsenide phosphide (GaAsP) green

gallium phosphide (GaP)

blue

silicon carbide (SiC)

ultraviolet, indium gallium purple, blue, green nitride (InGaN), gallium nitride (GaN) white

uses blue LED with fluorescent coating as wavelength converter

“Table Manner Table” (Source: Synthesis Studio)

“e-static Shadows” light installation (Prof. Dr. Zane Berzina in collaboration with an international research team; photo: David Rankalawon)

Surface illuminants or organic light emitting diodes are used in flat screens, cell phone displays, and digital cameras. Following the discovery of electroluminescence in organic materials as early as 1953, research into thinfilm materials for surface illuminants has been conducted for the past 20 years. These are more energy efficient to run than liquid crystal displays (LCD) and far easier to produce. The first OLED television was launched on the market in late 2007. Material concept and properties

OLEDs are made of several thin layers. The base layer measuring approx. 0.7 mm consists either of glass or polyethylene terephthalate (PET). An anode made of indium tin oxide (ITO) and a sandwich consisting of a light-emitting layer (EL) that contains colorant and is flanked by two transport layers, are fitted to it. A cathode is vacuumevaporated on the topmost layer, and the whole object is covered with another layer of glass or PET. After applying voltage, positively and negatively charged particles pass through the transport layers and meet in the emitter layer. The change in energy status causes the release of photons, which then become visible as light. OLED displays can be controlled within a microsecond and have a viewing angle range of 170°. The color temperature can be flexibly adapted to suit particular requirements or the time of day. Whereas for observers liquid crystals either visibly let through or block light emitted from a particular background, OLED displays generate light as soon as voltage is applied, thereby using less energy. Moreover, the images are higher in contrast. As no backlighting is required they can be manufactured just a few millimeters thick. No environmentally harmful substances are needed in the production process. Mass production is currently being prepared for roll-to-roll printing. OLEDs produced from polymers are called POLED or PLED.

173 Energy-generating and light-influencing materials

Properties  surface illuminant // made of several thin layers // controlled within micro-seconds // viewing angle range of 170° // high-contrast images Sustainability aspects  low weight and compact design // simple to produce and low production costs // energy-efficient operation

Organic light-emitting diodes (OLEDs)

Program mable rear window in the car study “Open Source - Light Car” using OLED (Source: EDAG)

OLED light branch (Source: Hannes Wettstein) Lamp with OLED (Source: Ingo Maurer)

Structure of an OLED

Light-emitting plastic

Glass cover

Conductive plastic Transparent anode

Electric current

Light

use

Apart from their suitability for all kinds of display, developers hope that OLED technology will enable large-surface illuminants and flexible screens. One vision is of illuminated surfaces appearing at any point on a glass or wall surface. Most people are familiar with future products such as electronic paper and luminescent wall-

paper. In the near future monitors on smooth furniture surfaces and brake lights in the rear windows of cars will be part of everyday life, as will luminescent wall elements in the foyers of shops and office buildings. To date, the short life span of blue OLEDs has been the biggest obstacle to their mass production.

The success of the iPhone clearly demonstrated that the future belongs to touch films that enable users to control electronic devices by moving their fingers. To date, systems available on the market were limited to two fingers only. In spring 2010, the Portuguese company Displax announced it had developed a wafer thin film that can recognize up to 16 fingers at once and also responds to movement of air. The contents to be displayed are projected on the film by means of a projector. Material concept and properties

174 Energy-generating and light-influencing materials

Properties  wafer-thin, flexible film // responds to up to 16 fingers at a time // also highly sensitive to movement of air Sustainability aspects  avoids the need for complex control technology // simple and compact design

Multi-touch films

The film consists of a polymer film with an integrated nanowire mesh. It can be curved and bent and, given its exceptional flexibility, can even be applied to spherical surfaces. The system is suitable for different bases. Successful tests have already been conducted for applications on wood, glass and plastics. The conductor paths integrated in the plastic are so sensitive to external influences that even blowing will suffice to have commands carried out. Use and processing

16-finger multi-touch film (Source: Displax)

The manufacturer’s idea is to turn virtually any surface into a digital input medium, meaning that even wardrobes could be used as interactive mouse substitutes. The new film system is just as suitable for small screens and conventional LC displays as it is for large installations and display windows. For outdoor use the system’s sensitivity can be calibrated according to the task at hand.

If an art enthusiast viewing pictures by Daniel Lergon has a light source behind him, his shadow and the abstract forms in the painting start to interact. A luminous garland of light similar to a halo (nimbus) appears around his silhouette.

Properties  interesting reflection characteristics // based on microscopically fine glass beads // use in fabrics or on concrete surfaces Sustainability aspects  reduces need for elaborate safety lighting

Material concept and properties

The apparition can be attributed to the retroreflective fabric Lergon used as a base for his paintings. Retro-reflective surfaces always reflect incident light precisely in the direction of the light source. The effect is produced by microscopically fine glass beads that are vaporized on to one side of the fabric base, together with an artificial resin blend. In a material development study currently underway at Kassel Technical University, retro-reflective properties are being transferred to concrete. Nanotechnological processes for magnetizing additives are being employed for the first

Retro-reflective materials

175

time to control the curing process and position the glass microspheres in the material matrix. use

Energy-generating and light-influencing materials

Retro-reflective surfaces are primarily used in fields where safety is an issue, and in fashion. Typical applications include reflective patches for cyclists and security staff. Retro-reflective fabric is also very popular in shoe design. In art, the material was discovered only recently. Reflective concrete, currently being developed under the name “BlingCrete”, is intended to be used for marking edges and hazardous areas (e.g., steps, platforms) and designing integrated building guidance systems and large structural elements. Given its special feel it can also be used in tactile guidance systems for the blind.

Use of retro-reflective fabric in painting (Source: Daniel Lergon)

According to theory, material is regarded as translucent if it does not absorb the light energy of a particular radiation. Glass and plastics such as polycarbonate and PMMA are materials typically used in optical applications and architectural facades. Until just a few years ago, the fact that concrete, wood and metals could in fact be permeated by visible light was considered inconceivable.

Building guidance system using “BlingCrete” reflective concrete (Source: TU Kassel)

Sustainability aspects  creates effects without elaborate lighting technology

Material concepts and use

Translucent concrete The development of translucent concrete can be attributed to the Hungarian architect, Áron Losonczi, who from 2002–2003 experimented with optical fibers and concrete at the architecture department of the Royal Institute of Art in Stockholm. By molding layers of fiberglass mats he eventually produced a new construction material featuring both load-bearing and translucent properties. Fiberglass content of 4–5% enables around 70% of the original light to be transferred from one side of a concrete block up to two meters thick to the other side, where it appears luminous on the concrete surface. Conversely, shadows appear on the other side of the stone surface as sharp contours. A concrete wall thus turns into both projection screen and light experience. It is capable of conveying the silhouettes of trees, houses and passers-by to the inside of a building. However, this is possible only in ideal climatic conditions, as the material is similarly bad at insulating heat as mineral panels are. Building blocks, bricks, panels, a lamp (LitraCube  ) and a wash basin by various manufacturers are now

®

Translucent materials ®

available under the brand names Litracon  , Robatex  and Luccon  .

®

®

Translucent wood In 2008, a light-transmitting wood composite material with a similar structure was launched under the Luminoso  brand. Fiberglass mats are layered between thin wooden panels and bonded using cold PU glue. The surface is completely sealed. The choice of wood, space between layers, and strength of the luminous fabric can influence the degree of light permeability. The wood used for

®

Translucent wood (Source: Luminoso ®)

backlit paneling and dividers in interior spaces and trade fair stands must be absolutely flawless, so as not to disturb the overall impression. A picture that is placed behind the composite panel will be transferred to the other side once it is lit from the rear. Even films can be projected on to the material.

176 Energy-generating and light-influencing materials

Translucent metal The crystalline structure of metallic materials makes it impossible for light to permeate them. In 2009, scientists in Oxford nonetheless succeeded in creating transparent aluminum. Using an X-ray laser, the electrons of an aluminum component were stimulated until it became transparent to ultraviolet radiation. The effect is known as saturation absorption and is based on the high intensity of the laser light employed. However, the permeable state could be maintained for a split second only.

Translucent bricks (Source: Robatex ®)

Harry Potter uses a cloak to become invisible to his friends and teachers at Hogwarts School of Witchcraft and Wizardry. There are those for whom invisible matter is pure fiction, while others view it as a lifetime’s research. In late 2008, US scientists managed to move one step closer to the solution. They claim to have developed what is referred to as a metamaterial with a nanostructured surface, which by way of diverting light radiation makes an object invisible to the human eye.

Material concept and properties

Metamaterials are composite structures consisting of metals, ceramic materials, polytetrafluorethylene and other composites. Their distinguishing feature is a surface that boasts a regularly recurring nanostructure smaller than the wavelength of incident rays of light. This structure directs radiation around an object in all three dimensions. The rays are neither reflected nor refracted. The material is shielded and completely invisible to the human eye.

Translucent concrete (Source: Litracon ®)

Properties  composite materials with regular nanostructuring // proportions smaller than the wavelength of incident rays of light // matter is shielded from visible light and sound waves Sustainability aspects sound-absorbing effects

Metamaterials To date, the only successful experiments known were on microwaves, whose wavelength exceeds that of visible light. In 2009 and 2010 scientists presented three new concepts for metamaterials,

whose shielding function could also function for rays of light in the visible spectrum. Only few incident rays are lost during diversion, which until now presented the biggest challenge to scientists.

The special optical properties could, for example, be produced through parallel silver wires meas­ uring 60 nanometers in diameter, embedded in an aluminum oxide matrix. To produce them, narrow ducts are etched into an Al2O3 block and electrochemically filled with silver. The result is a fine structure that is smaller than the wavelength of visible rays of light.

177 Energy-generating and light-influencing materials

Manufacturing procedure for a photonic metamaterial made of nanoscale gold spirals Electrolyte solution

+ Anode Gold complex

use

A second concept uses layers of magnesium fluoride and silver between 30–50 nm thick, which are stacked on top of each other using a vaporizing technique. These layers have a porous structure. Moreover, viewed through a scanning electron microscope a regular network becomes visible, in which wide parallel strips are connected to each other by thin bars. A third concept involves laser-cutting a structure into a photoresist. The cavities produced are galvanically filled with gold and the original polymer form is etched away. What remains is a structure consisting of several tiny, regularly configured gold spirals just a few hundred nanometers in diameter, which allow only one of the two possible rotational directions in electromagnetic waves to pass.

Scientists are doubtful whether it is actually possible to make 3D metamaterials, though ideas for how to use them have long since existed. There are numerous possible applications, for example, in the optics industry and as camouflage. More likely however, in the short term, given the lower costs, is the implementation of shielding systems for acoustic waves, which direct sound around specific objects. The perfect concert hall or vehicles without any background noise may indeed become reality in a few years. This particular field is being explored primarily by Spanish scientists at the University of Valencia, who are developing layered metamaterials.

— Cathode

178 Sustainable Sustainable production production processes processes

Multi-component Injection Molding…182 — InMold Techniques…182 — Metal Injection Molding…183 — Incremental Sheet Metal Forming…184 — Free Hydroforming…185 — Laser Beam Forming…186 — Arch-faceting…186 — Additive Forming …187 — Laser Structuring…187 — 3D Water Jet Cutting…188 — Multi­ functional Anodizing…189 — Dry Machining…189 — Adhesive-free joining…191

— 08 —

179 Sustainable Sustainable production production processes processes

180 Sustainable production processes

In addition to the material selected, it is primarily the manufacturing, and as such the production technology that has an influence on a product’s sustainability. Four different strategies have proved their worth in optimizing production processes’ environmental balance: 1. Combining various manufacturing principles enables environmentally harmful techniques to be replaced and the amount of environmentally damaging waste reduced. One example of this strategic approach is the application of laser technology for surfacestructuring molds for the production of decorative plastic components. Laborious electrical discharge machining and environmentally damaging etching are no longer necessary. 2. Another possibility for sustainable production is reducing manufacturing processes by producing molds in a single process step. In the case of metal injection molding, for example, complexshape components can be manufactured in a short space of time, which otherwise would have been possible only by means of laborious milling. 3. Integrating several functions in one component also reduces the amount of manufacturing involved. Examples are multi-component injection molding and what are known as InMold techniques, in which several different elements and materials are combined in a single mold. 4. Furthermore, over the last decade a number of other techniques have become established on the market that make it possible to produce complex components without high-cost molds. These include laser processing technologies and water jet cutting. Another prominent example is the use of hydromolding to produce sheet metal for lightweight construction purposes.

181 Sustainable production processes

“Plopp” inflated metal stool (Source: Oskar Zieta)

Laser beam-assisted shaping (Source: Fraunhofer IPT; photo: Adelheid Peters)

Laser beam hardening (Source: Fraunhofer IPT; photo: Adelheid Peters)

Water jet cutting (Source: Fraunhofer IPT; photo: Adelheid Peters)

Injection molding is the most economical process in the world for mass-producing plastic construction components. The technology also makes it possible to manufacture several components with different material properties and color schemes and/or to bind components made from plastic and another material together both loosely or tightly. Manufacturing concept

The processing of several different sorts of plastic in a single component is referred to as multicomponent injection molding. A highly complex molding tool assures that the various polymer materials reach the cavity at set intervals. This way, components with diverse property profiles can be produced, which in some cases have opposing qualities, in other words may be soft and firm at one and the same time. Injection molding the components separately and subsequently bonding them with one another is referred to as multi-shell injection molding. In this context assembly injection molding refers to a process, whereby mobile or rigid molds can be assembled during the injection molding process. In the case of InMold techniques, previously printed films or image labels are back-molded with plastic. The cost of printing or lacquering can therefore be significantly reduced.

182 Sustainable production processes

Sustainability aspects  reduced manu­ facturing, assembly and finishing // fewer components

Multi-component injection molding Application and processable materials

Injection molding plant (Source: Arburg)

In the mid-1980s, the possibility of backmolding films revolutionized the production of plastic parts with special decoration. Nowadays, InMold techniques are also used for components with wood and metal surfaces. The most well known method of processing is InMold decoration.

Properties  cost-effective production of plastic construction components in high volumes // integration of various materialities // assembly of various moving parts is also possible

Multi-component or assembly injection molding is used whenever medium to large numbers of complex, high-quality reproduction components with diverse properties are to be produced in short cycles. These are subsequently used in electrical devices, in automobile interiors, and in sanitation installations.

Properties  cost-effective decoration of plastic components // different material combinations possible // decors with integrated labeling possible // RFID label available Sustainability aspects  reduces number of manufacturing steps // no need for costly lacquering

Manufacturing concept

A printed image label on a foil tape is applied to the injection mold tool and then plasticized plastic injected behind the foil at high pressure. This dissolves from the foil carrier and is pressed against the form wall, assuming its geometry. People refer to InMold labelling when flat pieces of foil are laid in the tool individually and then injected. If semi-finished foil products made from polymer or metallic materials are punched out first and pre-formed and only then injected with plastic, people refer to foil insert molding.

1. Film cut // 2. Construction part after injection molding // 3. Construction part after injection compression shortly before punching // 4. Panel punched out with punched edge (Source: IWK)

InMold techniques

183

Application and processable materials

InMold techniques have proved their worth wherever pre-decorated molds are required for mass produced articles. Nowadays, this process can be used to produce even car glazing, displays and housing for electrical devices very efficiently. Various different material properties can be combined (for example, metals, textiles, wooden veneers), and decors with integrated symbols and light properties be produced. Back-injection molded metal foils are used in the field of sanitation. RFID InMold labels are available for optimizing logistics processes. The procedure is also suitable for processing solar films and for applying polymer-electronic elements such as OLEDs.

Sustainable production processes

Feedstock processing Nozzle side

Clamping side Metal film Cavity Embossed stamp

Tool structure

Injection

Melt

Embossment and punch

This injection molding process is now so advanced that it is suitable for the production of high precision metal components to precision levels of just a few micrometers.

Properties  injection molding of metal components // metal powder with thermoplastic binding agent // debinding following shaping by slow heating // shrinkage 20-30 % Sustainability aspects  efficient utilization of materials // minimal environmental damage owing to biodegradable binding agents

Manufacturing concept

Using conventional injection molding machines for the economical production of large numbers of metal components involves blending metal powder with thermoplastic binding agents or waxes and injecting it in the mold. The part can then be extracted from the mold and the binding agent be removed through heat treatment. During debinding the heat must be applied slowly to ensure that the part is not damaged during the liquefaction process. Polyvinyl alcohols (see p. 64), which dissolve in water and are biodegradable, provide an alternative binding material. Once the binding agent has been removed, the parts are heat-compressed and given their final mechanical properties. Shrinkage of 20–30% must be factored in when designing the parts.

Film back-molded parts for the vehicle interior (Source: Bayer MaterialScience)

Metal injection molding Process sequence in metal injection molding (Source: Arburg) Feedstock processing Powder

Green part production Binding agent

Extruder

Debinding

Sintering

Sinter shrinkage

184 Sustainable production processes

Cogwheels made by metal injection molding (Source: Arburg)

Previously, the production of large-scale sheet metal required expensive forming tools, which meant small numbers of complex-shape components could not be manufactured economically by deep drawing or stretching. For this reason, researchers in the tool machine laboratory at RWTH Aachen University developed a process that now makes this possible.

Application and processable materials

In principle, metal injection molding can be used for all metals and alloys that can be sintered. These include stainless steels as well as aluminum and copper alloys and precious metals. The biggest advantage over other processes is the possibility of producing highly complex molds in just one manufacturing step. Typical applications are casing for watches and parts for electrical appliances. The process is also used in the vehicle and aircraft industries, as well as in medical technology.

Properties  shaping of large-scale sheet metal // CNC-controlled shaping head // transfer of CAD data to the part // high reproduction accuracy // less expense for manufacturing tool molds Sustainability aspects  less manufacturing involved in producing sheet metal parts // low energy consumption through avoidance of high forming forces

Incremental sheet metal forming

Process sequence in incremental sheet metal forming (Source: beauvary)

Manufacturing concept

Application and processable Materials

With the new technology half the tools used in the forming process are replaced by kinematic forming, aided by universal tools. Shaping then occurs using a CNC-controlled shaping head, which partially reshapes the sheet in three dimensions. In this way the tool transfers the digital CAD product data onto the part. Flexible controlling even makes it possible to manufacture complexshape components without lengthy lead times. High reproduction accuracy, constant quality and low manufacturing costs are further advantages the process offers.

Sheet metal parts are used in lightweight structures in many areas of technology. Given the high degree of design leeway they offer, they are also frequently the base for several products’ brand image. As such, alongside classic applications in mechanical engineering, incremental sheet metal forming provides numerous opportunities in architecture and interior design. It can just as well be used for facade elements as it can for furniture finishes and wall elements for interior fittings, and it can be used for all typical materials in sheet metal parts.

Using high pressure to inflate hollow bodies is unusual with metallic materials. The automotive industry uses hydroforming processes to produce pipe profiles for exhaust systems efficiently. Since 2008, the Polish architect Oskar Zieta’s free inflating system has offered architects and fashion designers new potential uses.

185 Sustainable production processes

Properties  customized sheet metal parts form the base // forming under pressurization // accuracy of 0.1 mm possible // furniture and lightweight architectural structures Sustainability aspects  efficient production process for lightweight structures // avoids costly assembly stages

Free hydroforming Inflating process (Source: Oskar Zieta)

Manufacturing concept

Sheet metal parts that have been accurately cut on a laser cutting machine and then welded together at the edges form the starting point for the process. Air (or water) is then introduced at high pressure (up to 7 bar) through a valve, which forms the sheet metal and slowly creates a 3D body. Depending on the geometry, duration and pressure, the deformation process turns out differently. Special contouring of the sheet metal ensures that kinks form in certain areas, while in others load-bearing, cushion-like volumes that are accurate to one tenth of a millimeter emerge.

“Chippensteel” Chair collection (Source: Oskar Zieta)

Architectural trade fair stand at the 2010 IMM in Cologne (Source: Oskar Zieta; ph.: gee-ly)

Application and processable materials

The process is suitable, for example, for producing molds for the furniture industry without elaborate tools and stamps. In 2008 a stool named “Plopp” appeared on the market. A bench, a table frame and a lamp have also already been produced using the process. Oskar Zieta, who developed free hydroforming, is now planning to transfer the manufacturing principle to other areas and to produce lightweight structures for architecture (for example, for bridge construction). Tests have already been conducted on rotors for wind power plants and structures for passenger cabins. The first trade fair stand to be made of inflated structures was unveiled in January 2010, at the IMM fair in Cologne.

Clothes comb made using free hydroforming (Source: Oskar Zieta)

Ladder made using free hydroforming (Source: Oskar Zieta)

Production process for a bridge element (Source: Oskar Zieta)

Deep drawing, bending and pressing are the classic processes used to form a component in three dimensions. In some cases highly complex machine tools are required to create precisely defined shapes. Laser beam forming offers an alternative and highly flexible means of producing small quantities of sheet metal parts.

Manufacturing concept

Forming occurs by applying energy with a laser beam along the fold line. The sheet metal is heated along its surface edge. In proportion to the neighboring material areas, compressive stress is often created as a result of differing temperatures, prompting 3D forming. Using a laser, strictly demarcated areas can be warmed up such that a defined forming process can be initiated. Larger bend radii are possible by passing over the bending line several times.

186 Sustainable production processes

Properties  forming using a laser beam // complex shapes possible for components //large bending radii possible by passing over the bending line several times Sustainability aspects  reduced manufacturing involved // fewer complex tool molds are necesary // high-strength, lightweight construction components for vehicle manu­ facturing

Laser beam forming Application and processable materials

Although the laser beam forming principle has been known for several years, the technology is still at the prototype stage. It has the potential to make the production of complex sheet metal shapes cheaper, and to enable complex molds that

would not otherwise be possible with conventional technologies. The process is suitable for various metallic materials. Increasing bending angles occur in the following order: steel, titanium, stainless steel, copper, brass and aluminum.

Properties  based on natural selforganization // rectangular or hexagonal arched honeycomb structure // high loadbeating capacity and stability // low wall thickness and springback // favorable acoustic properties

The notion behind arch-faceting is based on the phenomenon of natural self-organization found in nature, for example in tortoise shells. In certain stress situations materials change rapidly from a flat surface to a rectangular or hexagonal arched honeycomb structure. In such cases the same amount of material is able to bear considerably greater loads.

Sustainability aspects  lightweight structures with reduced amount of material // high load-bearing capacity despite thin walls

Arch-faceting Roof of a sports stadium in Odessa with arch-facetted sheet metal (Source: Dr. Mirtsch GmbH)

Arch-faceted washing machine drum (Source: Dr. Mirtsch GmbH)

Manufacturing concept

Application and processable materials

For production purposes curved material is supported on one side, while pressure is applied on the other. The material reacts to the pressure and forms an energy-minimized 3D structure. This stands out for its high stability despite having thin walls and low springback. As such the process offers a material-saving alternative to typical forming techniques. The source material’s finish does not change as a result of the structuring process. Arch-facetted materials display favorable acoustic properties and emit less structure-borne noise. Furthermore, they promote heat exchange.

Arch-faceted products boast special visual qualities, which make them interesting for designers and architects. They can be produced regardless of the material and are suitable for architectural facades, lightweight roofs and vehicle interiors. With regard to products, the first washing machines, furniture, luminaire casings and reflectors are being equipped with arch-faceted structures. The technology is intended primarily for stainless steel, copper, titanium and aluminum structures.

3D prints, fabbing, laser sintering, stereolithography and laminated object manufacturing: whereas only ten years ago these processes were regarded as technological innovations, additive shaping has now advanced from being a niche market to a future growth area, notable primarily for its sustainability aspects.

187

Properties  additive structural principle // cost-effective individual component manu­ facture // based on CAD data // optimum material utilization, virtually no waste Sustainability aspects  avoidance of material waste during production // shapes can be produced to suit the human body or airflow conditions perfectly

Sustainable production processes

Additive forming Exposure to light of a layer of powder during laser sintering (Source: Fraunhofer IPT; photo: Adelheid Peters)

Manufacturing concept

Laser-generated metal structure (Source: Bego Medical)

These processes are based on a revolutionary manufacturing principle. Components are produced not by means of taking material away through milling and turning, but rather through an additive process. While in certain processes the material is fused in order to apply it through a nozzle guided by a plotter mechanism, the structuring principle in laser sintering is based on the localized fusion of material powder by means of a laser beam. Using 3D CAD data, complex shapes can be produced through the layered exposure of individual cross-sections of the component in a bed of powder.

techniques have now made the direct production of components possible. The processes are advantageous above all for the production of highly complex shapes with movable interior parts, which could not be realized by any other technology. By way of example, components could be designed to produce optimum airflow, thereby reducing energy consumption in vehicles. In medical technology additive manufacturing is used in the production of implants, which can be adapted to fit the human body perfectly.

Application and processable materials

Fabber-generated three-dimensional structure

Properties  insertion of decor by laser beam // no need for environmentally harmful etching and lacquering // individual production and small series // can be used on metal, glass, woods, ceramics, and organic materials Sustainability aspects  reduction of manufacturing stages // avoids coating and bonding processes

Whereas the various processes were initially used exclusively in the construction of models and prototypes, advances in materials and manufacturing

Fabber for self-construction

Lasers offer great potential for design-related professions, as they do away with the need for elaborate tools for cutting, welding, and drilling. This makes lasers particularly suitable for manufacturing small series and customized production. In the last few years several classic production processes have been replaced.

Manufacturing concept

Laser beam energy is ideal for applying decorative and delicate structures directly to material surfaces. In the process the material is either stained, fused or completely removed. In terms of flexibil-

Laser structuring

ity and environmental compatibility this makes marking lasers clearly superior to many coating techniques. In the production of molding inserts for plastic injection molding the laser beam’s energy is used to produce surface textures, which are visible later in the plastic components. This way, conventional processes such as complex electrical discharge machining, galvanic forming, and environmentally harmful etching can be avoided.

188 Sustainable production processes

Application and processable materials

Marking lasers are suitable for processing metal, glass, wood, ceramics, and various organic materials and can be used to remove coatings and lacquer from them. As a rule plastics are mainly stained or foamed. There is a wide range of fields of application, e.g., inscribing pacemakers, fruits, bathroom fittings, cell phones, watches, perfume vials, sunglasses and more besides. Lasers are also used in the production of solar panels, silicon chips, and switches and gear-shift units in cars.

Given the laborious programming and complex controls 3D water jet cutting has as yet been profitable to a limited extent only. For this reason the technique has been used predominantly in two-dimensional processing. Like the laser cutting process, it is of immense importance for complex contour cuts in components with low production volumes. By means of an optimized CAD/CAM connection and the use of five-axis systems as in milling, complex molds in three dimensions can now be cut economically.

Structuring mold inserts for plastic injection molding (Source: Fraunhofer IPT; photos: Adelheid Peters)

Properties  cost-effective incorporation of 3D cuts // production of cone-like molds // uses a thin, high-pressure water jet // for both hard and soft materials // CNCcontrol Sustainability aspects  separating technique involves neither grinding dust nor chips // no chemical air-pollution

3D water jet cutting

Manufacturing concept

Application and processable materials

The material is separated by means of a thin, high-pressure water jet, which is directed by a CNC control system towards the component being processed. The technique makes it possible to make cuts in tubes or free-form surfaces without pre-processing. With regard to design there are no limits. The surface quality of the cut edge is influenced by the jet’s feed rate. It depends on the material’s durability and hardness. 3D water cutting makes the production of cone-like molds possible.

The pure water jet is suitable for processing soft and tough materials (e.g., leather, textiles and foam materials); in the case of hard and viscoplastic materials the jet is mixed with a separating agent. The process is advantageous compared with other cutting techniques, in particular when the material would react sensitively to exposure to heat. This is particularly so in the case of textiles, plastics and glass. Water jet also has several advantages from an environmental perspective, as the processing produces neither dust nor healthendangering vapors.

Cone-shaped component made using a water jet (Source: Karodur)

Anodizing (also called eloxadizing is one of the most important techniques for finishing aluminum surfaces. It is based on the fact that aluminum reacts easily with oxygen. The aim of the process is to create a thick layer of oxide in a controlled manner.

189 Sustainable production processes

Properties  finishing of aluminum surfaces // production of functional layers // selfcleansing effect through micro-structuring // contact angle 160° when liquids atop Sustainability aspects  reduces cleaning intervals // lengthens life span of aluminum parts // scratch-proof coating recyclable

Manufacturing concept

In the anodizing process the positive-charge aluminum component is immersed in a bath with an electrolyte solution as a negative pole. An electrical current is applied, which results in positively charged water ions forming in the solution, creating a hard and resistant oxide layer on the material’s surface. This can be colored and assumes a decorative function. Given the gleaming transparency of the anodic layer, aluminum components can be colored without losing their metallic character.

Multifunctional anodizing

In order to give the coating other functional properties alongside its anti-corrosion qualities, it is now possible to produce a self-cleansing effect in aluminum parts by micro-structuring the anodized surface and subsequently treating it with a reagent. The ceramic-like surface repels almost all liquids atop it, which boast a contact angle of 160 degrees with a highly interesting visual effect.

Application and processable materials

Jar of cream with anodized surface (Source: Seidel)

When machining metallic materials (e.g., by milling or turning) it is common to use a lubricant to improve the quality of the finish and reduce wear. There are various emulsions and oils available that lower the temperature of the tool cutting edge and help remove the shavings. From an ecological point of view, however, the processing of metallic materials without lubricants seems more meaningful. For this reason, over the past few years, particularly hard cutting materials have been developed and investigations conducted on the process parameters that enable dry processing.

The process is currently undergoing qualification for use in mass production. Possible uses include, for example, self-cleansing cream jars for the cosmetics industry and water-repellent bathroom fittings. Should the relatively new process be used in the economical finishing of large aluminum surfaces, it could also be used for architectural facades.

Sustainability aspects  no lubricants used // no environmentally-harmful lubricant vapors

Dry machining

190

Manufacturing concept

As the different machining methods have different requirements with regard to cooling and the removal of shavings, dry processing is not an option for all procedures. Whereas milling, turning, and sawing offer plentiful opportunities, lapping, honing and grinding are if anything unsuitable. Drilling also poses problems for dry processing because without lubricants, removing the shavings from the drilling hole is difficult.

Sustainable production processes

In addition to the methods used, the material to be processed also plays a role when selecting the cutting material in dry processing. Particularly in the case of materials that are easy to machine such as magnesium, aluminum and cast iron, processing without or with minimum lubricant (MQL) is now widespread. Nowadays, there are also high-performance tools made of titanium and titanium nitride TiN for dry processing non-alloy and low alloy steels.

Milling with no lubricant (Source: Fraunhofer IPT; photo: Adelheid Peters)

Possible ways of dry machining different materials and procedures (MQL = minimum quantity lubrication) Material

Aluminium

Brass

Gray cast iron

Steels

Method

Casting alloy

Wrought alloy

Various alloys

GG20 GGG70

High alloy steels, rolling bearing steel

Machinetempering steel

Stainless steel quality

Sawing coating

MQL
 TiN

MQL
 TiN

Dry

Dry

MQL

MQL

(MQL)

Milling
 coating

MQL
 TiN+MoS²

MQL
 without

Dry/MQL

Dry TiN

Dry/MQL (Ti,Al)N, MoS²

Dry/MQL
 TiN

(MQL)

Hobbing

 coating

X

X

X

Dry TiN

Dry/MQL (Ti,Al)N, MoS²

Dry/MQL
 TiN

X

Drilling
 coating

MQL
 (Ti,Al)N

MQL
 without

Dry/MQL

Dry TiN

MQL (Ti,Al)N, MoS²

Dry TiN

(MQL) PVD (Ti,Al)N

Deep hole drilling coating

MQL


X

MQL

MQL


X

MQL

X

Thread cutting
 coating

MQL
 TiN

MQL

Thread molding
 coating

MQL
 CrN, WC/C

MQL

Turning
 coating

MQL

Broaching
 coating

Reaming
 coating

(TiAl)N+ Movic

TiN

(Ti,Al)N, MoS²

MQL
 Ti(C,N)

MQL
 TiN

MQL TiN

X

MQL

MQL

MQL

MQL Ti(C,N)

X

MQL
 TiN

Dry/MQL

Dry TiN

MQL TiN

MQL TiN

(MQL)

X

MQL

MQL

Dry MQL TiN

Dry/MQL
 Ti(C,N)multilayer

Dry/MQL
 Ti(C,N)multilayer

X

MQL
 (Ti,Al)N, PKD

MQL
 without

X

MQL PCD strip

(MQL)

MQL PCD strip

X

Inspired by the gecko, which, thanks to billions of extremely fine hairs on its feet, is able to stick to window panes, scientists have for some years now been attempting to transfer this natural mechanism from nature to industrial uses. The results are promising, and reveal a wide variety of possibilities for avoiding synthetic adhesives.

Manufacturing concepts and application

Adhesive textiles Adhesive textiles are materials that stick to any non-porous surface and do not lose their adhesive strength even after having been removed several times. They can be used whenever screens and glare shields are needed but where the architectural or design stipulations do not permit blinds or curtains. There are also printable versions for flexible decorations available on the market. Adhesive textiles boast particularly good self-adhesive properties when used on non-textured float glass, mirror surfaces, wall tiles, and lacquered wood. Nano hook-and-loop fastener Nanodimension hook-and-loop fasteners help fasten extremely small components in microproduction processes. They are based on a grasslike structure with nanoscale silicon needles. They are also known as “black silicon” (see p. 167). The needle-like structures hook onto each other and create robust connections. Applying low pressure releases the connection again. High joining forces produce permanently stable connections. From top to bottom, the needles are 300–900 nanometers in length. Silicon grass is also used to improve the efficiency of solar cells, as it does not reflect incident light. Wooden bonds and the use of lignin Permanent bonds between two wooden surfaces without adhesive are now possible. The components are rubbed against one another at a frequency of approx. 100 hertz until, on account of the heat generated, the lignin in the wooden structure melts and enters the open pores. Having cooled, the natural adhesive solidifies, producing a strong bond between the surfaces. The strength of the bonds is hard enough for the production of small wooden building components and furniture. Wood construction with wooden dowels Timber architecture adopts a very interesting approach to avoiding the use of adhesive and

191

Sustainability aspects  adhesives and odorous vapors avoided // swifter assembly processes

Sustainable production processes

Adhesive-free joining

Adhesive textiles to darken rooms (Source: Création Baumann)

chemical substances. Here, systems that consist of nothing but wood have been developed. Squared timber and wooden planks are stacked horizontally, flat, or diagonally to form compact building components, while bone-dry beech wood dowels penetrate the entire thickness of the layers. The dowels absorb residual moisture and swell irreversibly in the surrounding timber. The natural wood, which has not been bonded, creates a pleasant room climate and boasts high thermal insulation properties (thermal conductivity: 0.078 W/mK). Moreover, after use the wood does not have to be disposed off as hazardous construction waste.

Left: Wooden architecture with no adhesive (Source: Erwin Thoma Holz GmbH) Right: Wooden surfaces connected through vibration welding (Source: Berne University of Applied Sciences)

193 Appendix

About the Author…194 — Index…196 — Biblio­ graphy…205 — Selected Publications by the Author…206 — Selected Lectures by the Au­ thor…207

— Appendix —

194 Appendix About the author

195 Appendix About the author

Dr. phil. Dipl.-Ing. Dipl.-Des. (B.A.) Sascha Peters is the founder and owner of haute innovation in Berlin. An innovation consul­ tant, materials expert and engineer, his goal is to shorten innova­ tion processes and turn developments in materials into marketable products more quickly. Since 1997 Dr. Sascha Peters has gained widespread expertise in product development, innovation man­ agement, construction, and industrial design. He headed research projects and product developments at the Fraunhofer Institute for Production Technology IPT in Aachen, was deputy head of the Design Center in Bremen and head of the Modulor Material Competence Center in Berlin. Dr. Sascha Peters brings industrial use, university research and publishing activities together. In 2004 he was awarded a doctorate from Duisburg-Essen University for a thesis on improving communication between designers and engineers. Peters has written numerous specialist publications (for example the Handbuch für technisches Produktdesign (technical product design handbook)) and writes a column on materials for the magazine form. He gives lectures throughout Europe and runs workshops on materials, innovation and creativity management. In 2010/2011 he is staging the “Material formt Produkt” (materi­ als shape products) series of events for the Hesse Ministry of Eco­ nomics, Traffic and State Development. He also teaches “Material Technologies in Product Development and Design” at Kunsthoch­ schule Berlin-Weissensee. www.saschapeters.com

196 appendix Index A - c

3D prints 187 3D textiles 115, 116 — A — abaca 55 acetic anhydride 48 acetylated types of wood 48 acetylation 48 acetylation process 48 acrylic glass 43 aerated concrete 149 aerobic decomposition 66 aerogels 94 air chambers 106 air-suspension coating process 113 algae 15 algae cellulose 168 algae fiber composite 15 algae fibers 6 alginsulate 42 almond oil 154 almond shells 6 aloe vera 154 aluminum bronzes 76 aluminum foam 78, 104 aluminum laminate materials 98 aluminum shavings 78 aminoplast papers 58 ammonium sulphate 108 anodizing 189 anti-reflective coatings 156 antiseptic effect 156 Arachnoidiscus japonicus 144 aragonite platelets 144 aramid fibers 101 architectural textile 47 artificial muscle 130, 131

artificial resin panels 73 artificial turf 74 assembly injection molding 182 — B — bacterial fermentation 34 bacterial strain 43 Bakelite 6 balsa wood 86 bamboo 6 bamboo cane 47, 73 banana fibers 73 bark 58 bark cloth production 58 Barktex 58 basalt fibers 101 bath pearls 64 battery 158 bauxite 77 beeboards 96 beech wood dowels 191 biocomposites 32 bio crude plastics 35 biodegradable 62 bio-diesel 153 biological resistance 49 bioluminescence 170 bio-materials 32 bionics 142, 144 bioplastics 32 biopolymer 32, 36, 41, 55 bio resin 33 bio-technical foaming process 105 bitumen 109 black silicon 191 black solar cells 167 bleaching agent 89 BlingCrete 175 bone 144 bone substitute materials 144

brass 76 bricks 153 bridging threads 116 bronze 76 brown algae 53 Burnham Pavilion 115 butyl acrylate 127 — C — CA 38 cadmium telluride 164 CAD product data 184 CA foils 38 calcium carbonate 102, 144 camouflage 177 carbonates 153 carbon dioxide emissions 153 carbon fiber-reinforced 47 carbon footprint 8 carbon nanotubes 120, 131, 158 carboxylate 130 carboxyl groups 65 cardboard honeycomb panels 96 carrot fiber 32 carrots 55, 56 Cartamela 88 car wheel rim 144 casein 32 casein glue 109 cashew nuts 90 casting filters 103 castor oil 32, 40, 110 catalytic converter elements 113 catheters 127 cathode luminescence 170 cathode ray tube 170

197 appendix Index c - e

caustic soda 42 CelBloc Plus 149 cellulose 7, 32 cellulose acetate 36, 38 cellulose insulation systems 89 cellulose paper 158 cellulose plastics 7 cellulose triacetate 38 cement-bound chipboards 86 cement content 99 chalk 102 chemoluminescence 170 Chinese silver grass 38 chitin 32, 42 chitosan 42 Chlamydomonas reinhardtii 167 chlorine 89 chlorophyll 164 Chlorophyta 53 CISG solar cells 164 Cladophora algae 167 Cladophora green algae 168 Climate Change Package 7 Climate Conference 7 clinoptilolith 152 closed-cell foam structures 104 CNC-controlled shaping head 184 CNC control system 188 CO ² 34 CO ² footprint 34 CO ² storing properties 9 Cocodots 46 coconut 6, 55 coconut mosaics 46 coconut palm 46 coconut wood project 46 compostable bags 62

compounding 34 compound membrane with carbon fiber reinforcement 115 concentrator lens 166 conifer chips 86 cooling effect 169 cooling systems 169 copper 76 copper indium disulfide 164 copper indium gallium sulfur selenium compounds 164 copper-zinc 126 copper-zinc-aluminum 126 copper-zinc-nickel 126 copy paper 154 coral 153 cork 36, 108 cork oak 108 cork particles 50, 74, 86 cork-polymer composites 32 cornstarch 7, 37 covering layers 96 CPCs 50 crash absorbers 113 crude oil 6, 72 CTA 38 cube zeolite 152 cutting materials 189 Cyanobacteria 53 — D — damage caused by damp 108 dandelions 44 degrees of whiteness 89 dehydrating 54 de-inking process 89 device holders 105 diatom 53, 144 die-casting process 104 dielectric elastomers 130

doped semiconductor materials 168 double glazing 112 drinks cartons 70, 73 dry etching 166 drying agents 153 dual-component adhesive 159 dual-wall lightweight construction panels 116 dual-wall structure 115 duroplastic resin systems 72 dye-sensitized solar cell 164 — e — easy-to-clean properties 8 ecological balances 8 ecological rucksack 8 elastomer granulate 74 elastomer plastics 72 electrical 147 electrical current 145 electroactive polymers 124 electrochromic pigments 145 electro luminescence 170, 173 electroluminescent coating 171 electrolyte solution 189 electrospinning process 118 electrostatic field 118 elephant dung 88 elk droppings 88 eloxadizing 189 emulsions 189 energy-minimized 3D structure 186 energy requirements 94

198 appendix Index e - h

EPS 108 Eucalyptus timber 38 evaporating techniques 165 expandable polystyrene 102 expanded metal 104 expanded polystyrene 42 extrusion board 86

free inflating system 185 free inner pressure deformation 14 fresh fibers 89 frozen smoke 111 fungal species 54 fungus-based hard foam 9 —

— f — fabbing 187 fermentation 105 ferrofluids 148 fiber 152 fiber concrete 82 fiberglass 101 fiberglass mats 175 fiberglass-reinforced plastics 6, 121 fig tree 58 filament fibers 116 filler material 72 fine particles 151 fine-pore glass granulate 80 fire prevention gels 156 flake structure 106 flat loudspeakers 130 flax 55, 108 flexible screens 173 flexible skin 114 flock insulation 116 flow-resistance 148 fluorescence 170 fluorescent pigments 171 fluoropolymer 117 foamed glass 108 foam glass 82 foam glass granulate 81 foil insert molding 182 folding tent systems 114 fold line 186 formwork blocks 102

g — GaInP/GaInAs/Ge 166 gallium 70 gallium arsenide 164 gelatin 32 gels 145 geometry of the sphere 113 geo-textiles 34 GINA 114 glass 108 glass foam 80 glass from recycled bottles 82 glass microspheres 175 glass particles 79 glass powder 80 glow sticks 170 glycerin 37, 64 gold cadmium 126 granite 99 graphite platelets 102 green algae 162 greenhouse gas effect 153 guidance systems for the blind 175 gypsum construction panel 149

— h — hall constructions 117 halo 174 Haptophyta 53 heat 145 heat exchangers 113 heat shields 103, 113 heat-treated wood 48 heat treatment 48 hemicellulose 48 hemp 55, 108 hemp fibers 47 hexagonal honeycomb 120 high barrier film 111 highly reactive catalyst 154 high-performance plastics 72 high-pressure water jet 188 hollow metallic spheres 94 honeycomb 96 honeycomb cardboard 96 honeycomb cardboard panels 89 honeycomb core 73 honeycomb structure 87, 186 Honicel 96 hook and loop 167 hot air balloons 116 hot oil 48 household glass 78 hulls of wheat 105 human hair 119 hybrid fabric 114 hybrid materials 119 hydrogels 124 hydrogenase 167 hydromolding 180 hydrophobic 146 hygroscopy 37, 85 Hytrel ® RS 7

199 appendix Index i - m

— i — illuminating yarn 171 impact sound insulation 109 indium 70 indium tin oxide 173 injection-molded cork 51 injection molding 182 InMold decoration 182 InMold labelling 182 InMold techniques 180, 182 insect damage 48 interspersed granulate 74 invar 128 invisible matter 176 ionic polymer metal composites 130 iron-nickel 128 iron-nickel-manganese 128 iron-platinum 126 isocyanate 110 isocyanates 40 — j — jelly 132 jellying 132 jute 55, 57 — k — kenaf 55 kinematic forming 184

— l — lacquers 145 LA Design Challenge 119 laminaria algae 53 laminated object manufacturing 187 larch boards 48 laser beam 186 laser beam energy 187 laser cutting machine 185 laser processing technologies 180 laser sintering 144, 187 latex 43, 74 latex emulsions 109 latex lacquers 64 latex milk 44 layer of oxide 77 layers of graphite 120 lead-zirconate-titanate 129 leaf 152 leather industry 85 Lebast 149 light 145 light canopies 58 light colors 172 light concrete 88 light-conducting fabric 171 light refraction 148 lightweight materials 9 lightweight reinforcement elements 113 lignin 32, 48, 54, 191 lime powder 57 linseed oil 57 lipophobic 146 liquid crystal displays 173 liquid crystals 145 liquid wood 44 Livewire 126

loam construction panel 149 lotus effect 146 lotus flower’s self-cleansing process 119 lubricant 189 luminescence effect 172 luminescent wallpaper 173 Luminoso 13 Lunar Greenhouse 115 — m — machine-applied gypsum plaster 149 Maderón 52 magnetic field 147 mahogany 48 maize cobs 59 manganese-nickel copper 128 marking lasers 188 material efficiency 8 materials culture 10 maxit clima 26  149 meadow grass 108 mechanical memory effect 126 mediaeval glaziers 157 medical adhesive tapes 66 membrane textiles 83 memory foam 127 memory metals 126 Memry 126 metal foam 77, 78 metal foils 183 metal injection molding 64, 184 metallic character 189 metallic foams 14 metallic hollow spheres 9 metal powder 144 metal powder and binding agent suspension 104 methyl methacrylate 43

200 appendix Index m - p

micro-algae 153 microbes 35 microcapsules 154 microclimate 115 micro-invasive surgery 132 microorganisms 65, 66 micro-structuring 189 micro system technology 132 middle layer 96 mineral additives 102 mineral binding agent 82 miniature robots 132 MMA 43 modeling mass 107 monocrystalline photo voltaic modules 164 morphing materials 130 moss mats 151 multi-component injection molding 182 multi-layered fabric 116 multi-shell injection molding 182 multi-wall carbon nanotubes 120 muscles 144 mussel shells 80 — n — nacre 144 nanoclay 156 nanocrystalline silicon 155 nanodevices 119 nano-fibers 55 nano gold particles 158 nanometers 118 nano- or micro dimensions 8 nano quartz particles 156 nanostructuring 119 nanotechnologies 142 nano titanium dioxide 154

nanowires 158 natural biopolymer 38 natural cork 50 natural fiber composite 15 natural latex 85 natural self organization 186 natural silk 38 natural zeolite 152 neodymium 70 Neptune balls 108, 109 NeptuTherm 109 new silver 76 nickel-cobalt-iron 128 nimbus 174 nitinol 126 noise level 108 — o — oils 189 OLED television 173 oleophobic 146 olivine 153 one-way memory effect 126 open-cell foam structures 104 optical fibers 175 optical plastics 172 optical whitener 65 organic light-emitting diodes 173 organic manufacturing process 54

— p — paper pulp 107 papier maché 89 parking assistance systems 129 particle density 99 passive components 128 passive house 112 PBT 37 PbTe 168 PCM SmartBoard 149 PEP materials 130 peptone 159 Perlite 108 PET 34 PHA 35 Phaeophyta 53 phase-change materials 10 PHB 35 phenol 58 phenol resin 6 pheromones 118 phosphorescent materials 170 phosphorous 76 photochromic pigments 145 photocatalytic effect 154 photoluminescent materials 170 photoluminescent particles 171 photons 173 photosensitive memory polymers 127 photosynthesis 144 photovoltaics 164 piezo effect 128 piezo-materials 124 piezopolymers 130 PLA 34 plant mass 151 plastic blend 37 plastic sponge 104

201 appendix Index p - s

plastics reinforced with natural fibers 32 PLED 173 Plopp 14, 185 plus energy buildings 94 PMMA 43 polarizable micro particles 148 polar plastics 169 POLED 173 polyacrylic acid gels 132 polycaprolactone 62 polycrystalline silicon 164 polyester 37 polyester fabrics 117 polyetheroles 40 polyethylene 66 polyhydroxyalcanoates 35 polyhydroxybutyric acids 32 polylactides 32 polymer blends 72, 145 polymer cushions 83 polymer film 174 polymer materials 72 polymethyl methacrylate 43 polyol 40, 110 polypropylene 35 polypyrrol 168 polysaccharide 42 polystyrene 54, 66, 106 polyurethane 6 polyvinyl alcohol 37, 62, 183 polyvinylchloride 6 polyvinylidene fluoride 130 porous nanosheath 154 potato starch 32, 37 prefabricated wall systems 88 protective mats 74 PTFE 117 pulp 88 PUR 108 pure recycling 121 PVDF 130

PVOH 64 Pyrrhophyta 53 — q — quartz crystals 128 quartz watches 129 — r — radiation absorption 148 rags 88, 89 rain forests 46 ramie 55 rapeseed 153 rapeseed oil bath 48 recycled glass 78, 80 recycled tires 74 recycling 8 recycling of scrap cars 121 reflective concrete 175 refraction quotients 155 refractive index 111 release agent 64 retroflection 12 retroreflecting concrete 12 RFID InMold labels 183 Rhodophyta 53 rice 54 Ricinus Communis 40 rock wool 108 Rosensweig instabilities 148 rose petals 73 rotting 48 round granulate 81 rubber 32 rubber blends 43 rubber granulate 74 rubber tree 43 running tracks 74

— s — sandwich structure 59 saturation absorption 176 sawdust 105 scrap aluminum 77 scrap metal from cars 75 scrap steel 75 scrap tin plate 70 scratch resistance 8 scratch-resistant car paints 144 sea grassfill 108 seawater 153 seaweed 53 sebacic acid 40 secondary aluminum 77 self-cleansing effect 189 self-healing bioconcrete 159 self-healing materials 142 semi-crystalline areas 121 separating agent 188 shaped wooden tubes 50 shape memory alloys 124, 125 shape memory polymer 127 shavings 85 sheep droppings 88 sheep’s wool 108 sheep wool mats 109 sheet copper 76 SiGe 168 silanes 146 silicon aerogel 112 silicon coating 117 silicon cushions 116 silicon dioxide 155 silicon grass 166, 191 silicon needles 166 silver ions 157 silver threads 156 sisal 55

202 appendix Index s - w

sludge 66 snails 144 soft contact lenses 132 Solar Decathlons 10 solar films 183 solar generator 164 solar technology 10 sound absorbers 113 source of hydrogen 41 soy protein 90 spacers 115 spacing textiles 83 spinneret 118 stainless steel covering layers 98 stainless steel residue 75 standard everyday glass 78 staphylococcus aureus 157 starch 32 steamed red beech 48 steaming 48 steel fibers 98 stem circumferences 47 stereo-lithography 187 storage medium 148 storing properties 9 Styrofoam 102 suberin 109 sugar 32 sulfur diet 167 sulphonate 130 sunflower seed-shells 56 super absorbers 132 super-elasticity 126 super invar 128 surface illuminants 173 swelling and shrinking 48

— t — tamping 87 teak 48 TEG 168 temperature gradient 168 temporary architectural structures 116 textile concrete 116 textile membranes 117 textile-reinforced concrete 82 thermal conductivity 110 thermochromic pigments 145 thermo-bimetal strips 124 thermoelectric generators 168 thermoluminescence 170 thermo-mechanical compaction 49 thermotropically induced hydrogels 145 thickening agent 132 thin-film solar cells 162 thinking in material cycles 7 thread-shaped myzelium of fungi 54 timber construction 86 tin 76 tini-alloy 126 titanium 70 tool cutting edge 189 tortoise shells 186 touch films 174 tourmaline 128 TPS 37 TPS blends 37 translucency 145 translucent concrete 13 translucent wooden wall 13 transparency 145 transparent aluminum 176

transparent insulation panels 112 tree bark 6 tropical woods 48 two-way memory effect 126 — v — vacuum insulating panels 10, 108 vanadium oxide 145 vegetable oils 32 vegetable tanning agents 85 veneer plies 86 veneer strips 86 vibration welding process 41 viewing angle range 173 virtual water 8 visco-elastic foam 127 viscosity 147 viscous sugar syrup 34 volcanic glass 152 volcanic stone 101 VW Nanospyder 118 — w — washi paper 88 waste glass 79 waste materials 73 waste paper 106 water column 144 water film density 99 water ions 189 water jet cutting 180 water-sensitive concrete 14 water softening 153 water solubility 64

203 appendix Index w - z

water-soluble capsules 62 waxes 148 wheat 54 wheat starch 106 wheat straw 56, 86 white pigment 154 wind turbines 101 wood dust 105 wooden appearance 44 wood fibers 44, 85, 108 wood mixture 105 wood panel materials 85 wood particles 45 wood paste 105 wood plastic composites 32, 44 woolen proteins 118 World Cultural Heritage 58 wound dressings that decompose 62 WPC 32, 44 — x — XPS 108 — y — yeast 105 yeast extract 159 — z — zero-emission buildings 94 zinc oxide 145

204 appendix Bibliography

205 appendix Bibliography

Hirsinger, Q.: “Materiology – The Creative Industry’s Guide to Materials and Technologies.” Basel: Birkhäuser, 2009. Klooster, T.: “Smart Surfaces – and their Application in Architecture and Design.” Basel: Birkhäuser, 2009. Lefteri, C.: “Making It. London,” London: Laurence King Publishing, 2007. Leydecker, S.: “Nano Materials in Architecture, Interior Architecture and Design.” Basel: Birkhäuser, 2008. Lörcks, J.: “Biokunststoffe – Pflanzen, Rohstoffe, Produkte.“ Gülzow: Fachagentur Nachwachsende Rohstoffe e.V., 2006. Minke, G.: “Building with Earth. Design and Technology of a Sustainable Architecture.” 2nd rev. ed. Basel, Birkhäuser, 2009. Peters, S.: “Handbuch für technisches Produktdesign – Material und Fertigung”. Berlin, Heidelberg: Springer, 2006.

Peters, S.: “Material formt Produkt. Schneller in den Markt mit neuen Werkstoffen”, in the series Hessen-Nanotech, no. 18, edited by Hessisches Wirtschaftsministerium, 6/2010. Ritter, A.: “Smart Materials in Architecture, Interior Architecture and Design”. Basel: Birkhäuser, 2006. Sauer, C.: “Made of … New Materials Sourcebook for Architecture and Design.” Berlin: Die Gestalten, 2010. Schmidt, P. / Stattmann, N.: “Unfolded – Paper in Design, Art, Architecture and Industry.” Basel: Birkhäuser, 2009. Siebert-Raths, A. / Endres, H.-J.: “Technische Biopolymere.” Munich: Hanser, 2009. Thompson, R.: “Manu­facturing Processes for Design Professionals.” London: Thames & Hudson, 2007. Zijlstra, E.: “Materia – Material Index 2009”, Architectenweb bv, 2009.

206 Appendix Selected publications by the author

— Selected publications by the author — 10/2010 “Revolution der Materie: Das Ende des petrochemischen Zeitalters steht uns bevor,” in: Zukunftsletter, ed. by Verlag für die Deutsche Wirtschaft.

11/2009 “A world full of fabrics,” form 229, cover story, Basel: Birkhäuser.

3/2008 “My own factory,” form 219, Basel: Birkhäuser.

11/2009 “Full of ‘Hot’ Air,” form 229, Basel: Birkhäuser.

2/2008 “Nanotechnology and product design,” essay in “Nano Materials in Architecture, Interior Architecture and Design,” Basel: Birkhäuser.

9/2009 “Textile functioning worlds,” form 228, Basel: Birkhäuser.

9/2010

7/2009 “Injection molded decoration,” form 227, Basel: Birkhäuser.

“High-tech glass,” in: form 234, Basel: Birkhäuser.

5/2009

7/2010 “Material formt Produkt – Schneller in den Markt mit neuen Werkstoffen,” Hessen Nano-Tech series, ed. by Hessisches Ministerium für Wirtschaft, Verkehr und Landesentwicklung. 7/2010 “A new dimension of fibers,” form 233, Basel: Birkhäuser.

“Smart Materials,” form 226, leader in the special issue: The Magic of Materials, Basel: Birkhäuser.

1/2008 “Sharp light,” form 218, Basel: Birkhäuser. 11/2007 “New material Solutions,” form 217, leader in the special issue The Magic of Materials, Basel: Birkhäuser.

“In Zukunft ohne Öl,” form 225, Basel: Birkhäuser. 1/2009 “New nano-papers,” form 224, Basel: Birkhäuser.

“Plastics go mobile,” form 215, Basel: Birkhäuser. 5/2007 “Useful particles,” form 214, Basel: Birkhäuser. 1/2007 “Kommunikation im Wandel … Kreative Industrien erschließen Zukunftsmärkte im Web 2.0,” Magazin für Moderne Märkte, Bielefeld: ARGUZ Publishing.

3/2010 “Bioplastics,” form 231, Basel: Birkhäuser.

10/2008 Format “Wissenswertes,” background information about metals, synthetic materials, wood, paper, textiles and compos­ ite materials, modulor catalog 2009/2010.

8/2006 “Handbuch für technisches Produktdesign – Material und Fertigung, Entscheidungskriterien für Designer und Ingenieure,” ed. by Kalweit, A.; Paul, C.; Peters,

1/2010 “Phase-change materials,” form 230, Basel: Birkhäuser.

7/2008 “Adhesives,” form 221, Basel: Birkhäuser.

4/2010 “Sophisticated techniques,” in: imm visions cologne, published by Koelnmesse and Birkhäuser.

6/2003 with Pfeifer, T.; Voigt, T.: “Interdisziplinäre Kooperation im kreativen Entwicklungs­ prozess – Die Qualität der Kooperation zwischen Design und Engineering wird zu einer neuen Herausforderung für das Qualitäts­management,” in: QZ – Qualität und Zuverlässigkeit in Industrie und Dienstleistung. Munich: Hanser.

7/2007 3/2009

11/2008 “High Tech meets Low Tech,” form 223, leader in the special issue: Designing with Materials, Basel: Birkhäuser.

5/2010 “Translucent materials,” form 232, Basel: Birkhäuser.

7/2004 “Modell zur Beschreibung der kreativen Prozesse im Design vor dem Hintergrund ingenieurspezifischer Semantik.” Dissertation: University of Duisburg-Essen, Department of Industrial Design.

5/2008 “As pliable as granite,” form 220, Basel: Birkhäuser.

S; Wallbaum, R. Berlin, Heidelberg, New York: Springer.

4/2003 with Klocke, F.: “Potentiale generativer Verfahren für die Individualisierung von Produkten,” in: Zukunftschance Individualisierung. Berlin, Heidelberg, New York: Springer. 3/2003 with Voigt, T.: “DEGAP – Closing the gap between designers, engineers and marketers in product development processes in enterprises,” research project in the context of the “Innovation & SMEs” program of the European Union. 3/2003 “Was ist Kreativität – Zusammenarbeit von Designern und Ingenieuren,” commentary in: Der Konstrukteur, Mainz: Vereinigte Fachverlage. 11/2000 with Klocke, F.: “Wie Designer und Techniker ein Team werden,” in: ke konstruktion + engineering, Landsberg: mi Verlag Moderne Industrie.

207 appendix Selected lectures by the author

6/2000 “Produktionstechnologien und Strategien für die kunden­ individuelle Massenproduktion – Wettbewerbsvorteile durch Individualisierung von Produkten,” research project in the context of the “strategische Eigenforschungsprojekte SEF” program of the Fraunhofer-Gesellschaft. 12/1999 with Klocke, F.; Freyer, C.; Wagner, C.: “Selektives Lasersintern – neue Werkstoffe und neue Perspektiven,” in: VDI-Z, Düsseldorf: Springer-VDI.

— Selected lectures by the author — November 16, 2010 “Das Design einer revolutionären Materialkultur,” VDID Berlin-Brandenburg. November 5, 2010 “Materials as the motor for innovation,” Design Attack Festival, Krakow/Poland. October 27, 2010 “Nachhaltige Materialien und Multifunktionswerkstoffe für Designer,” Folkwang University, Essen. June 11, 2010 “Metallische Hohlkugel- und Schaumstrukturen für Design und Architektur,” 8th International Design Festival Berlin. January 28, 2010 “Zukunft entwickeln zwischen CO ² -Speicherung und auto­ nomer Robotik,” Hochschule für Gestaltung Offenbach. December 5, 2009 “Materials drive Innovation – Schneller zum markt­ fähigen Produkt,” lecture, design+engineering forum, Euromold 2009, Frankfurt/Main. November 16, 2009 “The Significance of Creative Professional for Material Based Innovation Process: from technological push to creative pull!” DRnetwork, Berlin.

November 13, 2009 with Hungerbach, W.: “Vom Material zum Produkt – Metall­ schäume und Hohlkugel­ strukturen in der Markteinfüh-

April 17, 2009 “Die Bedeutung von Designern für technische Innovationsprozesse,” 3rd Technisches Design symposium, Dresden.

rung,” face2face 9, Ludwigsburg. October 7, 2009 “Die Bedeutung von Designern für technische Innovations ­ prozesse,” 1. Design symposium on occasion of the award of the Lilienthal Designpreis 2009, Ministry of Economics, Labor and Tourism Mecklenburg-Western Pomerania, Wismar. September 30, 2009 “Smart, Intelligent, Kommunikativ – Materialien in neuen Dimensionen,” 2009 viscom conference, Düsseldorf. September 24, 2009 “The Impact of Creative Pro­ fessional on technical Innovations,” Stockholm School of Economics in Riga.

February 17, 2009 “Material as the Motor of Innovation – The impact of creative professionals on technical innovations,” keynote speaker, 3rd International Conference on Design Principles and Practices, Berlin. October 16, 2008 “Das Jahrzehnt der Materialien – Vom Technologie- zum Innovationsstandort dank professioneller Kreativer”, lecture at the conference “Creative Industries – Made by Design,” Zollverein World Heritage Site, Essen.

July 3, 2009 “Material und Innovation,” lecture, VDID NRW, Cologne.

February 15, 2007 “Kreative Industrien als Impulsgeber für eine erfolgreiche Innovationskultur,” keynote lecture, conference: “Erfolgs­faktor Design & Engineering,” Kommunikati­ons­verband Baden-Württemberg, Stuttgart.

June 24, 2009 “Revolution der Materie – Neue Werkstoffe für Designer,” Hochschule für Gestaltung, Schwäbisch Gmünd.

November 29, 2006 “Materialien und Fertigungs­ verfahren für Designer in der Automobilindustrie,” Euromold 2006, Frankfurt/Main.

June 17, 2009 “Auf dem Weg zur marktfähigen Innovation,” Material Vision 2009, Frankfurt/Main.

March 30, 2006 “Generative Verfahren im Design,” talk at the RPZ symposium “Rapid Prototyping und Design,” Speicher XI, Bremen.

May 16, 2009 “70% aller neuen Produkte basieren auf neuen Materialien,” experts’ forum at the 2009 Interzum, Cologne.

appendix Imprint

Translation from German into English: Gaines Translations Copy editing: Jill Denton Layout, cover design, illustrations and type setting: Pixelgarten, Frankfurt am Main, w w w.pixelgarten.de Printing: Engelhardt und Bauer, Karlsruhe, w w w.ebdruck.de Fonts: Neuzeit by Wilhelm Pischner, 1928 // Prestige Elite Std by Clayton Smith, 1953 // Minion by Robert Slimbach, 1990 // Agency by Morris Fuller Benton, 1932 Paper: Cyclus Offset // Cocoon Offset // Recyconomic Photo credits: page 134 copyright: Bayer MaterialScience // page 135 copyright: Bayer MaterialScience / Antje Schröder A CIP catalogue record for this book is available from the Library of Congress, Washington D.C., USA.

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LCR Hallcrest ™ 145 Ledano ® 85 Lederett ® 85 Liaver ® foam glass insulation 81 Lifocork ® 51 Lignobond 56 Litracon ® 175 Litracube ® 175 LockPlate ® 111 Luccon ® 175 Luminal ® 171 Luminex ® 171 Luminoso ® 175 Lupranol ® 40

Maderón 52 Makrofol ® 171 Makrolon ® Ambient 112 Makrolon ® AR 156 Maxit Clima 26 ® 149 Meadow grass 109 Megawood ® 45 Moniflex ® 38 Moso ® 47 Mowiol ® 65 m.pore ® 104

Paper made from animal excrement 88 Papercrete ™ 90 PaperFoam ® 106 PaperStone ™ 90 Parabeam ® 116 Parallam ® 86 © Patagonia 84 PCM Smartboard ™ 149 Pilkington Activ ™ 147 Plascore ® 96 Polyviol ® 65 Poraver ® foam glass granulate 81 Porocom ® 82 ProClimate ® 153 proSolve370e ® 155 Pure ® 121 Pure Moss ® 127 Pyrogel ® 112

N NaBasCo ® 56 NANOCLAY 156 Nanocyclodextrins 119 Nanogel ® 112 nanopaper 158 Nano-Quarz-Gitter ® 156 NanoSphere ® 119 Nanotol ® 147 Nano-X ® 119 Native ® bamboo 47 Natureplast ® 36 NatureWorks ® -Polymer 35 Neopor ® 102 Neptutherm ® 109 Nobody Chair 84

O OHT wood 48 Okagel ® 112 Ökopa plus 91

R Rastra ® 82 Recoflex 86 © Relight 80 Resopal ® -A2coustic 81 Reversacol™ 145 RheOil ® 148 Robatex ® 175 Rockglass ® 80 Rubex ® NaWaRo 40

S Salamander Bonded Leather 85 Seele Cover ® 118 Siotec ® 73 Smile Plastics ™ 73 SOCC Gran ® 74 Sokufol ® 64 Solid Poetry ® 146 Sorona ® 37 Stax ™ 79 Stelex ® 103 Subertres ® 51 SwissCell ® 96

TorHex ® 96 Trend Glasmosaike 79 Tretford veledo 85 © TTURA 80

u UWS 91

T Tectan ® 73 Tencel ® 38 Terramac ® 152 Thermofix ® 51 Thermofloc ® 107 Thermoholz Baladur ® 48 Thermowood ® 48

V Varia Ecoresin ™ 73 Variotec ® VIP 111 Veritex ™ 127 Vestamid ® Terra 40 Vinnex ® 51

W Waferboard 86 Waterfront 84 wellboard ® 90 Werzalit ® 45

x XYLOMER ® 45

Z zBoard 90 Zelfo ® 38 Zincopor ® 104